186 TRANSACTIONS OF THE ILLINOIS 



than nine o'clock at night. I think, as a rule, that the moth is nocturnal. 

 The case mentioned by Mr. Huggins is easily explained. Take male and 

 female, and put them in a bottle, and after copulation the female will try 

 to get out and lay its eggs, and I suppose they would continue to do so 

 until dead. 



There was a point made by Mr. Riley which I wish to notice ; he 

 was asked whether all parasites are not smaller than the insects upon 

 which they feed. There are some that are not much different in size from 

 those on which they feed. 



Mr. Riley — When I speak of largeness I speak of bulk. Of course 

 an insect might be much longer than another, and yet so small as not to 

 weigh half as much as the one on which it fed. It is a very simple prob- 

 lem that no parasite can be as large as its prey, or it could not exist. The 

 largest I know of is ophion macrurum, first obtained from the timber-belt 

 of our worthy President. This completely fills the cocoon of the moth, 

 and there is so little of the parasited worm left, that there is only the 

 shrunken skin, and sometimes barely that. But the most effectual are 

 those that are small. ^ 



