26 



with a " beak," which performs a very similar function to that 

 already noted as done by the needle, in giving a point where 

 pressure is brought to a focus, but not, as in the case of the needle, 

 applying all the force. 



In E. laiiestris the lid is not always quite so regular as in Lima- 

 codes, and a beak can hardly be said to exist on the pupa, but the 

 general process for rupture of the cocoon is almost identical with 

 that in Limacodes. In Lasiocampa quercfis exactly the same problem 

 is solved in an almost identical way, but the lid removed is very 

 irregular, and often fragmentary. 



In Centra the conditions and the results are very similar to those 

 in Lasiocampa. In this case a plentiful supply of softening fluid is 

 used to facilitate rupture ; the opening is nevertheless a fracture 

 produced by the moth exerting an end-to-end pressure within the 

 cocoon. 



In the allied LLybocampa the pressure is used to keep a sharp spine 

 in contact with the cocoon whilst it is carried round in an elliptical 

 line, applying softening fluid as it goes and at the same time scraping 

 through the softened silk and enabling the softening fluid to reach a 

 further layer, till at length an oval lid gives way to the pressure the 

 moth is exerting. 



There is no doubt that in the Lepidoptera at least the blood- 

 tension necessary to distend and expand the wings and other parts 

 after emergence is obtained by means of the inflation already fully 

 in action for emergence from the pupa. 



A similar inflation occurs in Lepidopterous imagines under at 

 least two other circumstances, in both instances in the Psychid.'e. 



In the case of the Fumeas, Luffias, and various Solenobias that 

 lay their eggs very rapidly within their larval sacs or pupa cases, and 

 that have after laying their eggs to arrange a certain amount of wool 

 as a protection over their eggs, I have observed in several species 

 that when the female has finished laying her eggs she is still quite 

 unreduced in bulk but is quite translucent, the place of the missing 

 eggs being taken by air. Why it is that also in many cases the 

 female simply shrivels up and completes her task without any 

 inflation I do not know. This certainly happens in very many 

 cases : when the inflated moth has finished her work the inflation 

 rapidly disappears, and she falls to the ground a shrivelled scrap, 

 just as if no expansion had ever occurred. 



In the case of two species of higher Psychids, Acanthopsyche atra, 

 L. {opacella), and Oreopsyche tenella, var. sermattensis, I have seen the 

 female moth drop out of the larva sac after completing oviposition, 

 inflated with air so as at first sight to look very much the same as 

 those moths that drop out of their cases full of eggs, as many do 

 that fail to be fertilised. 



In the case of the Solenobias and Fumeas the eggs are laid very 

 rapidly, often within half an hour. At first the moth is a distended 

 bag of eggs ; at the finish she is an amorphous mite, of perhaps a 



