HEARINGS AND DISSECTIONS OF TACHINIDiE. 101 



Tavo other European species — as yet undetermined, but which I refer 

 doubtfully to Masicera and Phorocera — both reared from Eupvoctk 

 chrysoi'}'h<pa^ have similar eggs and doubtless have the same habit. 



PROBABILITY OF AN EXTRA MAGGOT STAGE IN LEAF-OVIPOSIT- 

 ING SPECIES. 



It should be mentioned here that in all probability Blephnr'ipn 

 sciiteJlata^ Pales parkla, ZenUlla I'lhatr'ix^ and the other flies belong- 

 ing to this group have an additional maggot stage over other tach- 

 inids, since the neAvly hatched maggot is so very much" smaller in 

 size than are those of the latter. It ranges from one-tenth to one- 

 fiftieth the size of the newly hatched maggots of those species which 

 deposit eggs or maggots on the caterpillars, or maggots on the leaves, 

 and yet is often much larger in the last stage than are they. In such 

 case its second stage would correspond to the first stage of the other 

 tachinid maggots, and would not sIioav the last-stage type of anal 

 stigmata. This is the case with the maggot of P. par Ida above men- 

 tioned, which is evidently in its second stage and whose anal stigmata 

 do not yet show the four slits of the last-stage maggot. Each anal 

 stigma appears as a bifid plate with scalloped edge, indicating a fur- 

 ther split of each half at the next molt, which would produce the last- 

 stage type. 



THE DEPOSITION OF LIVING MAGGOTS BY TACHINID FLIES. 



A\ e come now to another phase of tachinid reproduction. It has 

 long been known that Sarcophaya and its innnediate allies deposit 

 living maggots. It Avas not definitely or generally understood, how- 

 ever, that many true tachinids do the same thing. A remark made 

 by Lowne in his Anatomy of the Blowfly, to the effect that both Sai'- 

 iopluKja and Tachina (these names evidently used in the wide sense.) 

 deposit living maggots, and the records cited by Brauer in Die 

 Zweifliigler des kaiserlichen Museums zu Wien, Volume III, that 

 Echinomyia grossa^ Miltogranima conica, and Trixa are larviparous, 

 are the only references I have seen to this fact. We found before we 

 had gone very far, however — in fact, this point developed Avith 

 Parexorista chelorrm — that female tachinids of certain species may 

 deposit eggs practically undeA^eloped, or at any stage of the develop- 

 ment of the embryo, or perhaps may even dej^osit living maggots. 



It should be stated here that the eggs of muscoidean flies originate 

 in tubes called the egg-tubes, a cluster of Avhich forms an ovary. The 

 egg-tubes of each ovary open through a single tube into the oviduct. 

 The eggs, upon reaching full size, pass from the egg-tubes of an oA^ary 

 through the single tube into the OA^iduct, at the loAver end of Avhich 

 they are fertilized by the male element proceeding from the minute 



