MORPHOLOGY OF THE LEPIDOPTERA. 171 



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 the 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 hy Weismann in 

 his account of the post-emhryonal development of the Muscidse (Zeitschrift fur wiss. 

 Zool. xiv. 1861, pp. 296, 297). Witlaczil has described in his ' Entwickelungsgeschichte 

 der Aphiden ' the formation of the vagina from an ectodermic 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 fin* wiss. Zool. xl. 

 1884, pp. 5.99, 605, 606). The same facts have been observed by Anton Schneider in 

 several insects {Coccus, Lep'mna, Acanthia, CMronomus, Tenebrio). His results are 

 stated very briefly and without illustrative figures (Zool. Beitriige, i. 1885, pp. 263, 261). 

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

 says that it was discovered by Herold in the male and female caterpillars of Pieris 

 brassicee. This statement is, however, erroneous ; no such discovery was made by 

 Herold, as the text of his memoir or of the abstract of it given p. 151 of this paper 

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

 Nussbaum in both sexes of two species of Pediculidae, Lipeurus bacilus and Goniocotes 

 hologaster, parasites of the Dove, and in Blatta orientalis ; but in the last named his 

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

 complete in the case of the 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. From 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 ' Zoolo°-ischer 

 Anzeiger,' v. 1882, pp. 637-643. 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. 1886). The formation of the reproductive organs is treated of on 

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



Nussbaum's conclusions, as summed up by himself on p. 642 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 efferent apparatus (uterus, vagina *, receptaculum seminis, 

 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 " here is applied to what is usually called vagina, and the term " vagina " means, according 

 to Miall and Denny, what is usually called genital pouch, so far, at any rate, as concerns the Cockroach. 



