680 C. B. HARDENBERG. 



Avould not be sufficient to reach the end of the abdomen of 

 the female (which lies head downward) so as to effect copula- 

 tion in the usual manner, and, as a matter of fact, this does 

 not take place. We have opened the bag's at various periods,, 

 from five to twenty minutes after the male had alighted, and 

 in no case have we seen the abdomen of the male extending 

 further than just inside the anterior edge of the chrysalis 

 case of the female. We are therefore inclined to believe that 

 copulation takes place in the following manner. The male 

 pushes up its abdomen through the neck of the bag until it 

 reaches the edge of the chrysalis-case of the female. Here 

 the abdomen is inserted for a short distance between the body 

 of the female and the pupa-case, the two prongs on the head 

 of the female probably acting as a guide, and the semen is 

 injected into the cavity of the chrysalis. The spermatozoa 

 travel upwards, assisted probably by movements of the female's 

 abdomen, until they reach the eggs which are being deposited 

 in the upper end of the chrysalis case, where they permeate 

 the mass and fertilise them. 



Apart from the apparent physical impossibility of the 

 normal method of copulation, we have the following evidence 

 which tends to support this view of the wa}^ in which fertilisa-^ 

 tion is accomplished : 



(a) Often some of the eggs have already been laid before 

 copulation takes place. 



(b) The freshly laid eggs are soft, and frequently polyhedral 

 through mutual pressure ; later, presumably after fertilisation 

 they become rounded and firmer. 



(c) The eggs are, as a rule, not all fertile ; between the 

 developing eggs there are found a number of such as have 

 remained soft and have shrivelled, showing that the sperma- 

 tozoa of the male did not permeate the entire mass. 



After the "copulation" is completed, the male withdraws 

 from the bag and flies away. Whether it is able to fertilise 

 another female we have not been able to ascertain. Although 

 conceivably this may happen under natural conditions, we 

 have never observed plural copulation on the part of the 



