BOMBYX MORT 477 



This gives a prolixity to every description under such circumstance, 

 which must afterwards appear tedious and even unnecessary ; and, of 

 course, in the end such descriptions and proofs are justly laid aside. 

 Therefore, as I mean in the following pages to describe some new facts 

 relative to the impregnation of the egg in the winged insect, I find it 

 necessary to prove the fact itself; which necessarily leads me to describe 

 the original observations, and the experiments in consequence of them. 



Reproduction, or new combination, is a property in the operations of 

 nature constantly acting; for every thing has a tendency to decay; 

 and this excites the attention of almost every thinking being. The 

 most simple change in matter may be productive of a new form ; but, 

 as many of the immediate causes of such changes are known, and 

 are even at the command of the human will, they have become familiar 

 to us and we regard them less ; but those which are more obscure 

 become the objects of closer attention and of direct investigation. 



Chemistry has gone far (abstractedly considered) in the reproduction 

 of properties in inanimate matter ; but, when compared with that which 

 is yet to be known, it must appear as nothing. The investigation of the 

 properties of animal bodies has been carried to greater length, because 

 it is connected with ourselves, and we become more interested in it ; 

 but much is left undone. 



The reproduction of animal bodies has always interested us much ; 

 for, besides its being a fit subject for philosophy, we are the more 

 nearly concerned, as we have a hand in it ourselves ; it is, even, the 

 ultimate of our' earthly enjoyment. Moreover, its being put under 

 restrictions by divine and human laws excites curiosity. 



Yarious are the modes of impregnation in the animal kingdom : they 

 are classable according to the class of animals ; and sometimes accord- 

 ing to the order of animals, and may even again be divisible according 

 to the different genera. But in the present investigation I shall con- 

 sider the subject no further than as it applies to the class of insects, 

 leaving the divisions to some future occasion, as they require a much 

 more extensive knowledge of the subject, the varieties being almost 

 without end. 



One would naturally suppose that the act of copulation, in the silk- 

 moth, was the inserting the penis into the vagina leading to the 

 oviducts, and there depositing the semen ; but, in dissecting the parts 

 of the female before copulation, as also after, I was able to ascertain 

 several facts. "When I dissected them before copulation, I observed the 

 bag above described [spermatheca] was empty. When I examined the 

 parts in those that had been impregnated, I found this bag full. Sus- 

 pecting this was the semen of the male, I opened the female as soon as 



