52 PARTHENOGENESIS 



behind of torn portions of the male sexual organs in the interior of 

 the female vagina, is, however, a circumstance which occurs not 

 unfrequently in other insects, especially in Beetles, With this 

 condition of the external sexual organs of the queen examined 

 by me, the state of the internal generative organs also agreed 

 exactly, for the seminal receptacle (seminal vesicle), which is 

 empty in all virgin female insects, was in this queen filled to 

 overflowing with spermatozoids (seminal filaments)*. This 

 queen therefore had returned to her hive certainly fertilized, and 

 would have possessed the power for a long time of effecting the 



* [The experiment by which Hunter distinguished the seminal-sac from the 

 poison-sac in the complex female apparatus of the Queen-bee is ingenious and 

 characteristic : " To ascertain which was the poison, I dipped points of needles 

 into both (bags), and pricked the back of the hand ; and those punctures that 

 had the fluid from the first-described bag in them grew sore and inflamed, 

 while the others did not."— Phil. Trans. 1792, p. 190. 



He applied this anatomical knowledge to explain the impregnation of insects, 

 as follows : — " Insects, respecting the males, are of two kinds : one, where the 

 male lives through the winter as well as the female ; and the other where 

 every male of that species dies before the winter comes on ; among which may 

 be considered, as a third, those where both male and female die in the same 

 year. Of the first I shall only give the common Fly as an instance ; of the 

 second I shall just mention all of the Bee tribe; and the third may be illus- 

 trated in the Silk-worm. The mode of impregnation, in the first, is its being 

 continued uninterruptedly through the whole period of laying eggs ; while in 

 the second, the copulation is in store ; and in the third, the female lays up 

 by the copulation a store of semen, although the male is alive." — Ibid. p. 185. 



Hunter then proceeds to detail a series of experiments made to determine 

 the influence of the contents of the spermatheca of the female Silk-moth 

 upon the eggs, " which experiments," he says, " may be applied to the Bee, 

 and many other insects." Of these experiments it will suffice to cite the 

 following as illustrating his knowledge of that part of the mechanism of the 

 female organs in the Moth and Bee on which so much of the important facts 

 in the present work depends : — 



" Experiment II. — I took a female Moth, as soon as she had escaped from 

 the pod, and kept her on a card till she began to lay. I then took females 

 that were fully impregnated before they began to lay, and dissected out that 

 bag which I supposed to be the receptacle of the male semen ; and, wetting a 

 camel-hair pencil with this matter, covered the ova as soon as they passed out 

 of the vagina. These ova were laid carefully on the clean card, and kept till 

 the ensuing season, when they all hatched at the same time with those natu- 

 rally impregnated. This proves that this bag is the receptacle for the semen, 

 and it gradually decreases as the eggs are laid."— Phil. Trans. 1792, p. 188.— 

 R. O.] 



