Francis Huber.
Pregny, 1. October 1791.
[N] So far from being torpid in winter, when the thermometer in the open air is several degrees below freezing, it stands at (86) and (88°), in hives sufficiently populous. The bees then cluster together, and move to preserve their heat.
Now that I am on the subject of thermometrical observations, I may cursorily remark, that M. Dubois of Bourg en Bresse, in a memoir otherwise valuable, is of opinion, that the larvæ cannot be hatched below (104). I have repeatedly made the experiment with the most accurate thermometers, and obtained a very different result. When the thermometer rises to (104°), the heat is so much greater than the eggs require, that it is intolerable to the bees. M. Dubois has been deceived, I imagine, by too suddenly introducing his thermometer into a cluster of bees, and putting them in agitation, the mercury has rose higher than it should naturally do. Had he delayed introducing the thermometer, he would soon have seen it fall to between 95 and 97, which is the usual temperature of hives in summer. In August this year, when the thermometer in the open air stood at 94, it did not rise above 99 in the most populous hives. The bees had little motion, and a great many rested on the board of the hive.
APPENDIX.
[The following passages are chiefly engrossed in the substance of the work, but the Translator, as has already been observed, for various reasons, judges it expedient to transfer them to an appendix. In his opinion these very minute details rather interrupt the connexion of the narrative, however interesting they may be considered, and they pertain more to researches purely anatomical.
The Translator has likewise in some instances incorporated several long and important notes with the text; because it appears to him that they actually belong to the substance of the treatise. These are the only variations from the original with respect to arrangement.]
Swammerdam has given an imperfect description of the ovary of the queen. He observes that he has never been able to find the termination of the oviducts in the abdomen, nor any other parts excepting those which he has described. "Notwithstanding all my exertions, I never could discover the site of the vulva, partly because I had not all my apparatus with me in the country, when investigating this subject, and partly from my apprehension of injuring other parts by pressure, which I had then occasion to examine. However, I have clearly observed a muscular swelling of the oviduct, where approaching the last ring of the belly; that it then contracts and afterwards dilates in becoming membranaceous. As I was desirous of preserving the poison bag, which is situated exactly here, along with, the muscles aiding the motion of the sting, I could follow the oviduct no farther. However, in another female, it appeared that the vulva is in the last ring of the abdomen, and under the sting. The parts expanding only while the queen lays, renders it extremely difficult to penetrate the aperture."
We have attempted to discover what has escaped the indefatigable Swammerdam. But his observation that the research can be made to the greatest advantage, at the time of laying, has paved the way to us. We have remarked that the oviduct did not issue from the body, but that the eggs fall into a kind of cavity, where they are retained several seconds before being laid.
On the sixth of August, we took a very fertile queen, and holding her gently by the wings in a supine position, the whole belly was exposed. She seized the extremity with her second pair of legs, and curved it as much as possible. This seeming an unfavourable position for laying, we forced her to stretch it out. The queen, oppressed with the necessity of laying, could no longer retain her eggs. The lower part of the last ring then separated so far from the upper part as to leave some of the inside discovered. In this cavity the sting lay above in its sheath. As the queen now made new efforts, we saw an egg fall into the cavity from the end of the oviduct. The lips then closed for several seconds; they opened again, and, in a much shorter time, dropped the egg from the cavity.