PACKARD. — INHERITANCE OF ACQUIRED CHARACTERS. 353 



It appears, then, that as the result of its semi-parasitic mode of life 

 the Campodea-form or triungulin larva of these iusects which have free 

 biting mouth-parts like the larva? of Carabida? and other carnivorous 

 beetles, instead of continuing to lead an active life and feed on other 

 insects, living or dead, and then like other beetles directly transform- 

 ing into the normal pupa, moult as many as five times, there being six 

 distinct stages, before the true pupal stage is entered upon. So that 

 there are in all eight stages including the imagiual or last stage. 



One cannot avoid drawing the very obvious conclusion that the five 

 extra stages, constituting this hypermetamorphosis, as it is so well 

 styled, were structural episodes, so to speak, due to the peculiar para- 

 sitic mode of life, and were evidently in adaptation to the remarkable 

 changes of environment, so unlike those to which the members of other 

 families of Coleoptera, the Stylopida? excepted, have been subjected. 

 The fat overgrown body and the atrophied limbs and mouth-parts are 

 with little doubt due to the abundant supply of rich food, the proto- 

 plasm of the egg of its host, in which the insect during the feeding time 

 of its life is immersed. Since it is well known that parthenogenesis 

 is due to over, or at least to abundant nutrition, or to a generous 

 diet and favoring temperature, there is little reason to doubt that the 

 greatly altered and abnormally fat or bloated body of the insect in 

 these supernumerary stages is the result of a continuous supply of rich 

 pabulum, which the insect can imbibe with little or no effort. 



The life history of the Stylopida? is after the same general fashion, 

 though we do not as yet know many of the most important details. 

 The females are viviparous, hatching within the body of the parent, 

 as I once found as many as 300 of the very minute triungulin larva? 

 issuing in every direction from the body of what I have regarded as 

 the female of Stylops childreni in a stylopized Andrena caught in the 

 last of April. The larva? differ notably from those of the Meloida? 

 in the feet heing bulbous and without claws, yet it is in general Cam- 

 podea-like and in essential features a triungulin. The intestine ends 

 in a blind sac, as in the larva? of bees, and this would indicate that 

 its food is honey. The complete life history of no Stylopid is com- 

 pletely known. It is probable that, hatched in June from eggs fer- 

 tilized in April, the larva? crawl up on the bodies of bees and wasps; 

 finally, after a series of larval stages as yet unknown,* penetrating 



* Westwood in his excellent account of tins group remarks " Ilenee, as well 

 as from the account given by Jurine, it is evident tliat the pupa of the Stylops 

 is enclosed in a distinct skin, and is also in that state enveloped by the skin of 

 vol. xxix. (n. s. xxi.) 23 



