576 BIOLOGY OF CHALCIDID^ HOWARD. 



rapid jj;i'owtli of the larva, a rapid cLange takes place and tbe alimentary 

 caual becomes narrow and elongated, tbe coecal extremity becomes 

 l)erforated, and by a rapid proliferation of cells the rectal tnbe is lined 

 with epithelinm and, with the change to pupa, the excrement is voided. 

 Of great interest in this connection are the recent observations of M. 

 E. Buguion upon the structure and life history of JiJncyrtus fuscicolUs, ;i 

 parasite of the European Hyponomeuia eognateUa (Receuil Zoologicpie 

 Suisse, v. 1890, pp. 435-70, reviewed in Journ. IJoyal Mic. Soc, 1891, part 

 3, June, p. 329). He found in the abdominal cavity of the caterpillars a 

 closed membraneous tube inclosing the" embryos" of the chalcid and 

 also the nutritive substance on which the larvii' feed. This tube seemed 

 to be formed by the ova themselves. According to his observations 

 the larva has au anus, quite in contradiction to the general statements 

 which 1 have just given. When the store of nutriment in this closed 

 tube is exhausted, according to M. Bugnion's observations, the larva^. 

 burst into the perivisceral cavity of the caterpillar where they feed 

 upon the lymph of their host. 



The question of the respiration of these internal feeders is more of a 

 puzzle. The probabilities are that subsisting entirely upon freshly 

 aerated blood, and in intimate connection with the air supply of the 

 host insect, sufficient oxygen is thus derived to purify their own circu- 

 latory fluid, rendering unnecessary any direct connection between their 

 stigmata and those of the host which Gerstaecker is said to have traced. 

 When we come to eg,g parasites the case becomes complicated and here 

 is a field for study. Ganin has shown a most curious hypermetamor- 

 phosis with the larv* of the proctotrypid genera Teleas, rolynevia, and 

 Flatygnsier (sic!) inhabiting eggs, and of the chalcidid genus Oph'wn- 

 urus, but their economy is not understood. We have in the Chalet- 

 <^i^ft! an egg parasite of a higher type than any of these in Uupelmus 

 and careful studies of the larval growth and economy of JEJ. mirahiUs, 

 for instance, which inhabits the large eggs of M crocentrnm are much 

 needed, particularly, as it seems to me, in this matter of its respiration. 



This whole branch of the subject has in fact been neglected, and a 

 most interesting field is here open for some careful worker. 



The large majority of chalcidid larva^ live within their hosts. As a 

 general rule, however, those wbich are parasitic upon leaf-mining and 

 wood-boring larva^, and in fact all endophytous larvje, feed externally; 

 and the same may be said of the larvse of the hyperparasites. The 

 growth of the larvfe of this class has not been carefully studied, although 

 Kewport (Trans. Linn. Soc. xxi, 83, 1852), has published many inter- 

 esting observations on the larva of Monodontomerus niiiduH which inhab- 

 its the cells of Anthophora, and is externally parasitic upon the larva^ 

 and i)upir of the bee. 



True external chalcidid parasites of ectophy tic larva? are rare and 

 belong maiidy if not entirely to the subfamily Elachisihuc. The larvse 

 of Eupkctrus, all of the species of which have this luibit, were studietl 



