MOEPHOLOGY OF THE LEPIDOPTERA. 17] 



only, the independent origin of the ovarioles and the efferent ducts of oviparous Aphides 

 (Ann. des Sc. Nat. 5, xv. no. 4, p. 43). But he regarded the vagina as a modified or 

 enlarged portion of tlie common oviduct {op. cit. (5), xiv. 1870, no. 9, pp. 7, 8) ; he stated, 

 however, at the same time, in the last-quoted memoir (pp. 8-11), that the accessory 

 female organs were outgrowths of the vagina itself, an origin surmised by Weismann in 

 his account of the post-embryonal development of the Muscidaj (Zeitschrift fiir wiss. 

 Zool. xiv. 1864, pp. 290, 297). Witlaczil has described in his ' Entmcivelungsgeschichte 

 der Aphiden ' the formation of the vagina from an ectoderinic invagination, and the 

 derivation of the oviducts from the ovarioles, and in the oviparous female the outgrowths 

 from the vagina which give rise to the accessory organs (Zeitschrift fiir wiss. Zool. xl. 

 1884, pp. 599, 605, 606). The same facts have been observed by Anton Schneider in 

 several insects [Coccus, Lepisma, Acanthia, Chironomtis, Tenebrio). His results are 

 stated very briefly and without illustrative figures (Zool. Beitrage, i. 1885, pp. 203, 26f). 

 To the ectodermic invagination in botii sexes he gives the name of " Herold's duct," and 

 says that it was discovered by Ilerold in the male and female caterpillars of JPleris 

 hrasslcce. This statement is, however, erroneous ; no such discovery was made bv 

 Herold, as the text of his memoir or of tlic abstract of it given p. 154 of this paper 

 will show. The most precise investigations on the subject have been made by Josepli 

 Nussbaum in both sexes of two species of Pediculidte, Lipeurus hac'Uus and Goniocotes 

 hologaster, parasites of the Dove, and in Blatla orientalls ; but in the last named liis 

 observations on the female were only carried out to a certain extent, whereas they were 

 complete in the case of tlie male. The account in extenso of his work was published 

 with figures in the Polish language, to which was added a German summary in 'Kosmos,' 

 Lemberg, 9th yearly issue. Prom the Naples ' Zoologischer Jahresberichte ' for the year 

 1884, p. 148, Arthropoda, I gather that he describes also in this paper the development 

 of the parts in Culex. I have not been able to see it, but in the record mentioned it is 

 stated to be essentially the same as the preliminary paper published in the ' Zoologischer 

 Anzeiger,' v. 1882, pp. 037-643. As to Blatta there is a brief account of the develop- 

 ment, signed by Nussbaum in Miall and Denny's work on the Cockroach (Studies in 

 Comp. Anat. iii. 1880). The formation of the reproductive organs is treated of ou 

 pp. 193-195, and iigures given of the developing parts in the male. 



Nussbaum's conclusions, as summed uji by himself ou p. 042 of the ' Zool. Anzeiger,' v. 

 are to the following effect : — 



(1) The current impression that the larval ducts unite with one another and give 

 origin to the whole system of sexual ducts is incorrect ; they form only the vasa 

 deferentia or the oviducts. 



(2) All other parts of the eflFerent apparatus (uterus, vagina *, receiitaculum serainis, 

 ductus ejaculatorius, penis, and appended glands) develop from the hypodermis. 



(3) The connective tissue and the musculature of the efferent apparatus are derived 

 from mesoblast cells present in the body-cavity. 



(4) The efferent ducts originate as paired rudiments. All azygos parts (uterus, penis, 



* The term " uterus '" hero is applied to what is usually called vagina, and the term " vagina '" means, according 

 to iliall and Denu}-, what is usually called genital pouch, so far, at any rate, as concerns the Cockroach. 



