476 INSECTA. 



or holders on the tail of the caterpillar. Their use is to hold in the 

 time of copulation. At the anus are two horny hooks for the same 

 purpose. For, when they copulate, they hold the female so fast as to 

 allow her to hang by this hold ; and I have seen them lay hold of 

 another by the wing so fast, that they could be lifted up by it. 



The internal parts consist of two testicles, one on each side, situated 

 about midway between the anterior and posterior end of the belly, and 

 near to the upper surface of the back. The two together would make 

 about p^th of the size of the whole animal. They appear as if com- 

 posed of three or four smaller bodies rounded and a little compressed 

 together. Each testicle has a duct which emerges out of it, in the 

 hollow on their inner side, very similar to the ureter in the kidney. 

 Tbese ducts pass towards the anus in a convoluted course, and then the 

 two unite into one duct. 



At this part they are considerably enlarged. At this union enters a 

 duct which is formed of two blind beginnings. The common duct or 

 union of the whole is of considerable length, and is coiled up with the 

 others in the natural state, and terminates at last in the penis. The 

 penis is a horny substance, which is capable of being projected and 

 drawn in, and is in a distinct part, not in the anas as in birds, yet they 

 both open between the two last scales. 



As soon as the chrysalis has emerged from its cell and got into the 

 moth-state, they are fit for copulation, which takes place as soon as a 

 male and female meet. The male appears to be in search of a female, 

 and when he finds her, he immediately tarns his side to her and bends 

 his tail towards her, and creeps round her in this way, fluttering his 

 wings, making a kind of rattling noise, touching her with his tail as he 

 goes round, and when his tail comes in contact with her they then close. 

 As she is the larger of the two, and probably the stronger, she often 

 draws him after her. 



They keep in contact ten, twenty, or thirty hours, and when they 

 separate she often squirts out a transparent fluid, only a little yellowish ; 

 and about two hours after the separation she begins to lay her eggs. 

 After having laid some eggs, they will take the male a second and a 

 third time ; indeed they will take the male several times, even before 

 they begin to lay their eggs. They will take the male after they have 

 laid all their eggs, even till they are almost dead ; and often die in this 

 state. 



Observations on impregnation. — In science, whenever a new fact or 

 principle is discovered, it becomes necessary to establish and prove it 

 by observation and experiment ; whereas in things already known and 

 admitted, it becomes only necessary to describe the fact or principle. 



