New observations on the natural history of bees Part 10

We procured a number of queens according to Schirach's method for the purpose of dissection, and set them at liberty that they might seek the males. The first which did so, was seized the instant she returned, and without dissection spontaneously exhibited what we were so impatient to behold. Examining the under part of the belly, we saw the oval end of a white substance which distended the s.e.xual organs. The belly was in constant motion, by alternate extension and contraction. Already had we prepared to sever the rings, and by dissection to ascertain the cause of these motions; when the queen curving her belly very much, and endeavouring to reach its extremity with her hind legs, seized the distending substance with her claws, and evidently made an effort to extract it. She at last succeeded, and it fell before us. We expected a shapeless ma.s.s of coagulated fluid; what therefore was our surprise to find it part of the same male that had rendered this queen a mother. At first we could not credit our eyes; but after examining it in every position, both with the naked eye, and a powerful magnifier, we distinctly recognised it to be that part which M. de Reaumur calls the _lenticular_ body, or the _lentil_, in the following description.{O}

'Opening a drone there appears a portion formed by the a.s.semblage of several parts, often whiter than milk. This on investigation is found to be princ.i.p.ally composed of four oblong pieces. The two largest are attached to a kind of twisted cord, fig. 4. r, called by Swammerdam the root of the p.e.n.i.s; and he has denominated seminal vessels, s. s. two long bodies that we are about to consider. Other two bodies oblong like the preceding, but shorter and not half the diameter, he calls the _vasa deferentia_, d. d. Each communicates with one of the seminal vessels near, g. g. where they unite to the twisted cord, r. From the other extremity proceeds a very delicate vessel, which, after several involutions, terminates in a body, t. a little larger, but difficult to disengage from the surrounding tracheae. Swammerdam considers these two bodies, t. t. the t.e.s.t.i.c.l.es.

Thus there are two parts of considerable size, communicating with other two still thicker and longer. These four bodies are of a cellular texture, and full of a milky fluid, which may be squeezed out. This long twisted cord, r, to which the largest of the seminal vessels is connected, this cord, I say, is doubtless the channel by which the milky fluid issues. After several plications, it terminates in a kind of bladder or fleshy sac, i. i. In different males this part is of various length and flatness. By calling it the _lenticular_ body, or the lentil, it receives a name descriptive of the figure it presents in all males whose internal parts have acquired consistency in spirit of wine. The body, l. i. is therefore a lentil, a little thickened, of which one half, or nearly so, of the circ.u.mference is edged along the outline by two chesnut coloured scaly plates, e. i. A small white cord, the real edge of the lentil, is visible, and separates them. This lentil is a little oblong, and, for convenience, we shall ascribe two extremities to it, the anterior and posterior. The anterior, l, next the head, is where the ca.n.a.l, r, dividing the seminal vessels is inserted, and the opposite part; i. next the a.n.u.s, the posterior. The two scaly plates, e. i.

e. i, proceed from the vicinity of this last part, whence each enlarges to cover part of the lentil. Under the broadest part of each plate, there is a division formed by two soft points of unequal length; the largest of which is on the circ.u.mference of the lentil.

Besides these two scaly plates, there are two others, n. n. of the same colour, narrower, and fully one half shorter, each of which is situated very near the preceding, and originates close to the origin of that it accompanies, namely, at the posterior part of the lentil.

The rest of the lentil is white and membranaceous. From behind proceeds a tube, k. a ca.n.a.l also white and membranaceous, but it is difficult to judge of its diameter, for the membranes, of which it consists, are evidently in folds. To one side of this pipe is attached a fleshy part, p. somewhat pallet shaped, one side is concave, and the edges plaited; the other side is convex. In certain places the plaits rise and project from the rest of the outline, and form a kind of rays; the pallet appears prettily figured. Though lying with the concave side applied to the lentil, it is not fixed to it. Swammerdam seems to consider this pallet as the characteristic part of the male.

'Though the parts we have described are the most conspicuous in the male, they are neither those which protrude first, nor when protruded are the most remarkable. On viewing from the opposite edge of the lentil, forming the division of the two great scaly plates, a sac or ca.n.a.l, k. proceeding from the posterior part of the lentil, there is distinctly visible the body u, which we call the arc; where there are five transverse hairy bands of a yellow colour, while the rest is white. This arc seems out of the membranaceous ca.n.a.l because it is covered only by a very transparent membrane. One end almost reaches the lenticular body, and the other terminates where the membranaceous ca.n.a.l joins the folded yellow membranes, m. which form a species of sac, that is applied to the sides of the aperture, adapted for the genital organs pa.s.sing through. These reddish membranes are those that appear first on pressure, and form this elongated portion, at whose end is a kind of hairy mask. Finally, with the sac formed by the reddish membranes, there are connected two appendages, c. c. of reddish yellow, and red at the end, s.

These are what appear externally like horns.{P}'

The lenticular substance, l. i. provided with each scaly lamina, are the only parts of those described by M. de Reaumur, that we have found engaged in the organs of our queens. The ca.n.a.l, r, by Swammerdam denominated the root of the p.e.n.i.s, breaks in copulation; and we have seen its fragments at the place where it unites to the end of the lentil, l. towards the anterior extremity; but we have found no traces of the ca.n.a.l, k, formed of involuted membranes, which in the body of the male proceeds from the posterior end of the lentil, l. i. nor of the plaited pallet, p. adhering to this ca.n.a.l, called by Swammerdam the p.e.n.i.s from its resemblance to that of other animals, though he is not of opinion that this point, which is not perforated, can perform the functions of a real p.e.n.i.s, and hold the princ.i.p.al part in generation.

The ca.n.a.l, k, therefore, and all appertaining to it, must break at i, quite close to the posterior part of the lentil, since we found no remains of the lenticular bodies left by the fecundating males, in the body of our females. The ca.n.a.l, r, which Swammerdam calls the root of the p.e.n.i.s, with greater reason than he was himself aware, is not extended in the body of the male as represented by the figure here engraved, but this long twilled ca.n.a.l consists of several involutions, from the seminal vessels whence it proceeds, into the lenticular body where it terminates, and where it conveys the fluid. This ca.n.a.l therefore can extend during copulation, and allow the lenticular substance to protrude out of the body of the males.

It is evident this may be the case during copulation as is seen on opening a drone, for, by endeavouring to displace the lenticular body, the involutions of the cord disappear, and it extends much more than necessary for the lentil to protrude from the body; and if we attempt to separate it farther, the ca.n.a.l breaks at l. close to the lentil, and at the same place where it breaks in copulation.

By dissection two nerves are discovered, towards the origin of the ca.n.a.l, r. inserted into the seminal vessels and distribute in them, and towards the root of the p.e.n.i.s many ramifications undoubtedly serving for the motion of these parts. Two small parts, perceptible near the nerves, are two ligaments for retaining the generative organs in their proper place, so that except the root of the p.e.n.i.s, they cannot be drawn out without some exertion; it and the lenticular body however can protrude, and actually do so during copulation. A certain degree of pressure forces all these parts from the body of the male, but they spontaneously return, and appear reversed.

Swammerdam, and after him M. de Reaumur have admired this mechanism; they have thought, indeed, that the return should be occasioned by the effect of the air inflating the parts, and they supposed that the male organs proceeded from the body, and returned during copulation, the same as when forced out by pressure. Following their example, we have pressed them from the body of many males; we have a thousand times witnessed this wonderful return, which they detail with the greatest precision; but our males never survived the operation. We have seen, as M. de Reaumur, a few males protrude them spontaneously, even some of the parts inverted, but at that moment they died, and were unable to retract the parts which a pressure, most likely accidental, had forced out. Thus it is improbable that the male organs protrude by turning out of themselves in copulation; and the details which follow prove incontestibly, that it is otherwise. Had not Swammerdam been prejudiced with this opinion, he would have seen that the lenticular body can proceed from the body in erection without reversing itself; he could have proportioned the tortuous ca.n.a.l, which he calls the root of the p.e.n.i.s; he would have seen that, at certain times, it can be sufficiently extended to allows the lenticular substance to protrude; he would have discovered the real use of the scaly plates; he would have explained that of the ca.n.a.l k, of the plaited pallet q, and the movements of all these parts, more admirable perhaps than the inversion which he was the first to observe.

Our observations incontestibly prove copulation. The portion of the males found engaged in the body of our queens, hitherto called the lenticular substance, may be denominated a p.e.n.i.s both from its position and use. The same surface is presented by it in the queen as in the body of the male, which is proved by the position of the laminae, e. e.

attached to the interior of the p.e.n.i.s, when found in the queen. It is evident, if the supposed inversion took place, the laminae would be found within the posterior part of the p.e.n.i.s; and we should see them through its membrane, by their concave side, instead of which the convex surface is presented when in the v.u.l.v.a of females, the same as in the body of the males. But what is the use of these laminae? From their figure, hardness, relative position with respect to each other, and their situation at the extremity of the p.e.n.i.s, we cannot doubt they are real pincers. However, to ascertain the fact, we found it necessary to see their position, and that of the p.e.n.i.s itself in the females. For this purpose, we prevented some of the queens from extracting the parts left by the impregnating males, and by dissection we discovered that the laminae were pincers as we had conjectured.

The p.e.n.i.s was situated under the sting of the queens, and pressed against the upper region of the belly. It was supported by the posterior end, against the extremity of the v.a.g.i.n.a, or excretory ca.n.a.l. There we were sensible of the motion and use of the scaly pieces. Their extremities were separated a little more than in the male, and pressed between them some of the female parts below the excretory ca.n.a.l. The extreme minuteness of these parts prevented us from distinguis.h.i.+ng them clearly, but the effort necessary to separate and remove the p.e.n.i.s from the female, satisfied us of the use of these laminae.

Inspecting a male from above, the convex side of the plates, e. e. is presented, and the summit of the angle formed by their origin. When in the body of the female, they are in the inverse position; what was above in the male is now below, and the extremity of the pincers directed upwards. This makes us suspect that in copulation the male mounts on the back of the female, but we are far from a.s.serting it positively. It may be asked whether that part we call the p.e.n.i.s, is the sole part introduced into the female during copulation? We have carefully investigated this, and can affirm, that it is the only one of all those described by M. de Reaumur, which has been found in our females. But we have discovered a new part that escaped both him and Swammerdam, which appears from the following experiment.

Separating the lenticular substance from the excretory ca.n.a.l, where it was attached, we drew along with it a white body, adhering by one extremity, and having the other engaged in the v.a.g.i.n.a. Towards the end of the lentil, where the substance adhered, it appeared cylindrical, then it swelled, and again contracted, to dilate anew in a greater degree than at first; afterwards it contracted and terminated in a point. A powerful magnifier was required to see all this. When pulled from the lenticular body, the part was commonly broke, and also when extracted by the queens from themselves. The figure and situation seemed to authorise our considering it the p.e.n.i.s itself, and the lenticular body only an appendage. But the last queen we examined exhibited a peculiarity that induced us to doubt the fact, and led us to suspect that this body is nothing else than the seminal fluid itself, moulded and coagulated in the v.a.g.i.n.a, and which from its viscosity adheres to the lenticular substance, and accompanies it when separated from the v.a.g.i.n.a. In this queen was found a little extravasated white matter, near the opening of the v.a.g.i.n.a. This, though at first liquid, soon coagulated in the air as the seminal fluid of drones does. In separating the lenticular body from the v.a.g.i.n.a, we drew along with it a thread which broke near the lentil; and seemed of too little consistence for the p.e.n.i.s of a male. The lenticular bodies, found in our queens, appeared larger than in the males we dissected, and we have remarked with M. de Reaumur, that these parts are not of equal size in every male.

_Experiment 1._--On the tenth of July, we set successively at liberty three virgin queens four or five days old. Two flew away several times; their absence was short and fruitless. The third profited better by her liberty; she departed thrice; the first and second time her absence was short; but the third lasted thirty-five minutes. She returned in a very different state; and in such as allowed no doubt of her employment, for she exhibited the part of a male that had rendered her a mother. We seized her wings with one hand, and in the other received the lenticular body, of which she had disengaged herself with her claws. The posterior part was armed with two pincers, e. e. sh.e.l.ly and elastic, which could be drawn asunder, and then resumed their original position.

Towards the anterior part of the lentil appeared the fragment of the root of the p.e.n.i.s; this ca.n.a.l had broke half a line from the lenticular body. We allowed the queen to enter her habitation, and adapted the entrance so that she could not leave it unknown to us.

On the seventeenth we found no eggs in the hive; the queen was as slender as the first day; therefore the male, with which she had copulated, had not impregnated her eggs. She was again set at liberty; after twice departing, she returned with evidence of a second copulation. We then confined her, and the eggs she afterwards laid proved that the second copulation had been more successful than the first and that there are some males more fit for impregnating queens than others. However, it is very rare that the first copulation is inefficient; we have only seen two that required it twice; all the rest were impregnated by the first.

_Experiment 2._--On the eighteenth we put at liberty a virgin queen twenty-seven days old, she departed twice. Her second absence was twenty-eight minutes, and she returned with the proofs of copulation. We prevented her from entering, and put her under a gla.s.s to see how she would disengage the male organs. This she was unable to accomplish, having only the table and sides of the gla.s.s for support; therefore we introduced a bit of comb; thus providing the same conveniences as are in a hive. Fixing herself on _it_ by the first four legs, she stretched out the two last, and extending them along her belly seemed to press it between them. At length introducing her claws between the two parts of the last ring, she seized the lenticular body, and dropped it on the table. The posterior part was provided with sh.e.l.ly pincers, under which and in the same direction was a grey cylindrical body. The end farthest from the lentil was sensibly thicker than that adhering to it, and terminated in a point. This point was double, and open like the bill of a bird, which induces us to think the body was broken, a conjecture supported by the following experiment.

_Experiment 3._--On the nineteenth we set at liberty a queen four days old; she departed twice; her first absence was short; the second lasted thirty minutes, and then she returned with the marks of fecundation. As we wished to obtain the male organs entire, it was necessary to prevent the queen from breaking them by extracting them with her feet; we therefore suddenly killed her, and cut off the last rings in order to lay the v.u.l.v.a open. But though deprived of animation, so much life remained in these parts that the lenticular body was thrown out spontaneously. Under the pincers appeared the remnant of a cylindrical body which had broken near the origin and remained in the female. This body was very small at the origin; it afterwards sensibly enlarged; next contracting by degrees, it terminated in a sharp point. We found the point engaged up to the gland in the excretory ca.n.a.l, and the rest in the v.u.l.v.a.

_Experiment 4._--We set two virgin queens at liberty on the twentieth.

The first had been abroad on the preceding days, but the scarcity of males prevented her from being previously fecundated. She returned with the organs of a male. We tried to prevent her from extracting them, but she did this so expeditiously with her feet, that we could not accomplish it. She was then allowed to enter the hive.

The second queen departed twice. Her first absence was short as usual; the second lasted about half an hour, and she returned impregnated.

Having killed her as suddenly as possible, we laid open the v.u.l.v.a. The lenticular body was deposited as in every queen hitherto dissected; the pincers were situated under the excretory ca.n.a.l. Some parts not easily distinguishable were pressed between the laminae, and their office seemed to consist in forcing the extremity of the lentil to approach the orifice of the v.a.g.i.n.a, and apply so forcibly to it that some exertion was necessary to separate them. We previously examined them, with a very powerful magnifier. Then a peculiarity which had escaped us was perceptible. In drawing out the lenticular body, there proceeded from the v.a.g.i.n.a a minute part, v. adhering to the posterior end of the lentil, and situated below the plates. It spontaneously retracted into the lentil, like the horns of a snail. It appeared white, very short, and cylindrical. Under the pincers was a little half coagulated seminal fluid at the bottom of the v.u.l.v.a. Though much could be expressed, there was none pure; it was almost liquid, but soon coagulated, and formed a whitish inorganic ma.s.s. This observation carefully made removed all our doubts, and demonstrated that what we had taken for the p.e.n.i.s of males was nothing but the seminal fluid, which had coagulated and a.s.sumed the interior figure of the v.a.g.i.n.a. The only hard part introduced by the male, was the short cylindrical point which retracted into the lentil, when we separated it. Its situation and office prove that it is there we must look for the issue of the seminal fluid, if we can hope to find an opening, when not engaged in copulation.

We found this new part in the first drone we dissected. By pressing the seminal vessels, the white liquid then escaped downwards to the root of the p.e.n.i.s r. and into the lenticular body, l. i. which became sensibly swoln. We prevented the fluid from returning, and by new pressure of the lentil forced it to advance. However, none escaped, but we saw at the posterior end of the lenticular body, and under the scaly pincers, a small white cylindrical substance, the same in appearance as that we had found engaged in the v.a.g.i.n.a of the queen. This part retracted on pressure, and then returned.

I request you, Sir, while perusing this letter, to inspect the figure of the male s.e.xual organs published by M. de Reaumur, and which are copied here. The descriptions are most accurate, and present a just idea of the situation of these parts when in the male's body. We readily conceive how they appear when left in the female by copulation. This detail will sufficiently indicate the situation and figure of the new part I have discovered.

I suspect that the males perish after losing their s.e.xual organs. But why does nature exact so great a sacrifice? This is a mystery which I cannot pretend to unveil. I am unacquainted with any a.n.a.logous fact in natural history, but as there are two species of insects whose copulation can take place only in the air, namely, ephemerae and ants, it would be extremely interesting to discover whether their males also lose their s.e.xual parts, in the same circ.u.mstances, and whether, as with drones, enjoyment in their flight is the prelude of death.

FINIS.

FOOTNOTES:

{O} Memoires sur les Abeilles, p. 450.

{P} Such long and minute descriptions can be very imperfectly translated; indeed they are unintelligible without microscopical inspections of the parts themselves.--T.