88 THE ENTOMOLOGIST. 



reproduced in the drawing below will be seen by the aid of a 

 good glass. No. 1 is the female : it will be seen that there is a 

 black blotch in the middle of a yellowish tint, and which in 

 natural size is not larger than a large pin's-head. In the male, 

 which is No. 2, it is the same blotch at the same place, but in 



SEXES OF LEPIDOPTFROUS LARViE. 



the middle is a dark green spot, which gives the appearance of a 

 hole : this is only from the internal organs, and is of a liquid 

 substance ; for should a larva of each sex be killed and emptied, 

 nothing of the signs will remain. By this means of telling the 

 male from the female, I have no doubt advantage will be gained, 

 as in the case of the Tusser-worm, reported by Claud Dumaine 

 (Entom. xix. 110), the female cocoons only being picked for 

 breeding purposes : the female and male could thus be picked 

 within a very short time. 



[Having been asked to express an opinion upon Mr. Weniger's 

 communication, I can affirm that the position in which the sexual 

 characters are stated to be is that in which such characters would 

 occur if they were proved to be present. This, in itself, is a strong 

 argument in favour of the accuracy of Mr. Weniger's observation. 

 Nevertheless, I do not think that the characters can be equally 

 marked in all larvae, for I have frequently examined the large 

 larvse of Sphingidse in this very area and with this very object in 

 view. It is quite clear that, as Mr. Weniger implies, the markings 

 have not the value of external organs of reproduction, but if their 

 presence is confirmed they will prove to be the blind terminations 

 of the ducts of the sexual glands, which should be found beneath 

 the cuticle at this very spot, as Herold showed, in the case of the 

 larva oi Pieris brassicce, towards the beginning of this century. It 

 is unfortunate that so new an observation is not supported by a 

 quotation of the numbers of individuals in which the characters 

 were proved to correspond with the respective sexes. If con- 



