THE 



MONTHLY MICROSCOPICAL JOURNAL. 



AUGUST 1, 1874. 



I. — The Presence of Balhianis Nucleus in the Ovum of 

 Osseous Fishes. By Dr. Van Bambeke. 



We know that according to M. Balbiani the ovule is not so simple a 

 structure as is generally believed ; * by a series of researches extended 

 over nearly every class of animals the distinguished French em- 

 bryologist is assured that besides the germinal vesicle considered 

 as the nucleus of the egg-cell, one finds a second nucleus -whose 

 function " consists essentially in bringing about the separation of 

 the elements, till then indifferent, of the protoplasm of the young 

 ovule into a germinal part, and a nutritive part, grouping around 

 the one the materials destined to form the plastic part or the germ 

 whence is later formed the embryo, while the other or simply 

 nutritive material remains around the germinal vesicle."! Hence 

 the name vesicule embryo fene given by M. Milne-Edwards to 

 Balbiani's vesicle. 



We know then generally the great importance from the point of 

 view of embryology of Balbiani's discovery. But, as he says himself 

 in his last work, " his conclusions have been combated by various 

 authors." And in a very recent memoir upon the egg and its 

 development in osseous fishes, published by one of the first embry- 

 ologists in Germany — Herr W. His — there is no mention whatever 

 of Balbiani's vesicle.| This it is which leads me to communicate 

 the present paper to the Society of Medicine at Gand. 



In studying the ovarian egg of osseous fishes I am certain that one 

 finds in ovules of a certain age, l)esides the germinal vesicle, another 

 nuclear mass, viz. le noyau de Balbiani.^ Without stopping for a 



* "Oil the Constitution of the Germ in the Animal Ovum before Fecundation "' 

 ('Oomptea Kendus,' 1864, t. Iviii., pp. 584-588, 621-625). A short expose of 

 Balbiani's mode of view, accompanied by three figures (after the author), has 

 been inserted in the form of a note by Dr. Eunvier in his translation of Frey's 

 'Treatise on Histology,' p. 103. 



t Balbiani, ''Me'moire sur le De'veloppement des Arane'ides " ('Annales des 

 Sciences Naturelles,' 5" Se'ric, tom. xviii., p. 33). 



X Wilhelm His, ' Ilntersuchungcn iilDcr das ei und die Eientwickelung bia 

 Knocken-fischen,' mit 4 Tafeln, Leipzig, 1873. We think we recognize Balbiani's 

 vesicle in tlie egg of the Barbel, Fig. Id of Plate II. of His' essay. 



§ I have rarely found the vesicular form, but generally that of a more or less 

 granular mass. For this reason, and not to prejudge the function of the organ, I 

 have replaced here the expressions vesicule de Balbiani and vesicule emhryogme by 

 that of noyau de Balbiani. 



VOL. XII. r 



