BOMBYX MOUI. 479 



written account of the experiment upon it, and was kept in a box by 

 itself. In tbe ensuing season, eight of the ova hatched at the same 

 time with others naturally impregnated. ' 



The ova laid by females that had not been impregnated, did not stick 

 where laid ; so that the semen would appear not only to impregnate 

 the ova, but also to serve for attaching them when laid. 



Finding that I could impregnate the completely formed eggs with the 

 semen of the male without the act of copulation, I now wanted to 

 know whether that bag in the female silk-moth which increased at the 

 time of copulation was the semen of the male. 



Experiment 2nd. — I took a female moth as soon as she escaped from 

 the pod, and kept her on a card till she began to lay her eggs. 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 for the 

 male semen, and wetted a camel-hair pencil with this matter, covering 

 the ova [of the virgin moth] as they passed out of the vagina. These 

 ova were kept upon this clean card, and kept carefully until the ensuing 

 season, when they all hatched at the same time with those naturally 

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

 and this gradually decreases as the eggs are laid. To prove this still 

 further, I made the following experiment. 



Experiment 3rd. — I took a female after being fully impregnated by 

 the male, and dissected out the bag or receptacle for the male semen. 

 This operation affected the animal so much, that she laid very few of 

 her ova. Those she did lay were kept carefully on a clean card. The 

 ensuing season several of them hatched at the same time with the 

 others. This experiment contradicts the others. But perhaps the bag 

 was not cut off close to the vagina, or that, in cutting it off, part of 

 the semen might have been squeezed into the vagina, and so have 

 impregnated them : however, it was observed that these ova hardly 

 stuck to the card. 



The above experiment I repeated the following year, when the animal 

 being weakened by the operation, she only laid seven eggs, which did 

 not hatch. 



Experiment 4th. — To see whether a female could be impregnated after 

 the bag for containing the semen was taken out, I dissected out the 

 bag and closed up the wound by applying a piece of the wing of another 

 moth over the wound, which very soon stuck firmly by the blood coagu- 

 lating; I then allowed a male to copulate with her the usual time. 

 She laid all her ova, which were kept till the ensuing season, and they 

 all hatched. It may be conceived here that the semen might get out 

 at the duct of the bag into the abdomen, and by the exertions made to 



