THE VICTORIAN NATURALIST. 71 



present case, however, no such economy of labour is found, for 

 the parasites of the Antheraea fill up the interior of the cocoon 

 with a series of cells, arranged in a very haphazard manner, but 

 each parasite having a cell to itself; this accomplished they rest 

 secure in the habitation thus unknowingly provided for them until 

 the time when young Antheroea larva? are once more about. 

 Owing to this arrangement of single cells each fly has to make an 

 opening for itself, and this is effected with the strong mandibles 

 which the insects possess. Like the Antheraea, a revolving motion 

 is maintained during the action, by which means a neat exit is 

 finally made. 



The apparatus used by Cosmotriche vitulina, Don, another 

 moth constructing a hard cocoon, is upon the same principle, but 

 in this case instead of having the instrument placed upon the 

 wings, it is formed by an extension of the scapulae. 



I had intended to have investigated the external anatomy of 

 several more species before bringing forward these notes, but on 

 consideration I thought it best to put before you my observations 

 up to date, and I think that if others having opportunities to 

 investigate the subject will take the trouble to do so it will be 

 found that the strongest and most useful part of a cocoon-making 

 lepidopterous insect is the base of the wings, where the costal, 

 median, and sub-median nervures are united into a solid corneous 

 mass, and that the plausible and generally accepted theory of an 

 acid secretion has little foundation in actual fact — the fluid which 

 is observed being universal to all pupae, including those which are 

 not closed at all. It is probably not secreted by the perfect 

 insect, but is the surplus moisture over that required for a proper 

 development. The empty pupae cases of the Hawk Moths are 

 frequently half full of liquid ; especially is this the case with C. 

 celerio, which has a large chrysalis compared with the size of the 

 insect, and as this species makes but the merest attempt at a 

 cocoon — in fact, frequently simply pupates on the surface — it can- 

 not have any connection with its escape. On the other hand, we 

 sometimes observe specimens which, through having been fed on 

 dried-up food, are devoid of sufficient moisture, and these are 

 generally cripples — that is, although they can escape from their 

 cocoons or chrysalis without the aid of moisture, they cannot 

 properly develop their wings, which are therefore crumpled or 

 deformed. It must also be remembered that the tongue of a 

 moth, while in the pupa case, is extended from the head down- 

 ward and sheathed all the way ; it is not until after its escape 

 that the insect can make use of it or coil it up, so that no 

 secretion could be applied from the mouth or tongue. The 

 question is one of some interest, and I shall be very glad to hear 

 the opinions or experiences of brother entomologists with cocoon- 

 making moths, either Australian or foreign. 



