[419] Gegenbaur, Waldeyer, E. van Beneden, Eimer.
[420] Carlberla, Zeit. f. wiss. Zool. Bd. XXX.
[421] Loc. cit.
[422] [Quarterly Journal Microscopical Science, July 1878.]
[423] [This Edition, p. [252].]
XIII. On the Existence of a Head-Kidney in the Embryo Chick, and on Certain Points in the Development of the Müllerian Duct[424]. By F. M. Balfour and A. Sedgwick.
(With Plates 27 and 28.)
The following paper is divided into three sections. The first of these records the existence of certain structures in the embryo chick, which eventually become in part the abdominal opening of the Müllerian duct, and which, we believe, correspond with the head-kidney, or “Vorniere” of German authors. The second deals with the growth and development of the Müllerian duct. With reference to this we have come to the conclusion that the Müllerian duct does not develop entirely independently of the Wolffian duct. The third section of our paper is of a more general character, and contains a discussion of the rectifications in the views of the homologies of the parts of the excretory system in Aves, necessitated by the results of our investigations.
We have, as far as possible, avoided entering into the extended literature of the excretory system, since this has been very fully given in three general papers which have recently appeared by Semper[425], Fürbinger[426], and by one of us[427].