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The Rete-Cords and Sex-Cords of Chrysemys 
The following table will show the great difference of opinion held by 
authors working upon the same identical species. The view held is in- 
dicated in the same manner as above. é 
Lacerta agilis—Weldon (B) ; Hoffmann (B); Mihalkovies (C). 
Chick (Gallus)—Waldeyer (A); Semon (B); Mihalkovies (C) ; 
Laulanie (C); Schmiegelow (C); Janosik (D); Weldon (?). 
We cannot close an account of the literature upon the subject without 
reférring to the work of Semon, g1, upon Ichthyophis, one of the Gym- 
nophiona, and a paper by Semper, 75, upon the Sex-glands of the 
Elasmobranchs. 
Semon, gi, considers the nephrotome to be the ventral portion of the 
mesoblastic somite. This view, by the way, is also held by Brauer, o2. 
Semon states that after the nephrotome breaks away from the myotome 
and sclerotome, it still remains attached to the peritoneum (unsegmented 
mesoderm) by means of two bridges of cells—a lateral and a medial. 
The major part of each nephrotome forms a Malpighian corpuscle of the 
mesonephros. The lateral of the two bridges connecting it with the 
peritoneum becomes its peritoneal funnel (nephrostome), while the 
medial bridge sends out a process which divides into a dorsal branch pass- 
ing to the adrenal body, and irregular branches (sex-cords) non-seg- 
mental in character, that pass to the sex-glands, there to come in 
contact, in the case of the male, with the seminal vesicles, which are 
derived from the germinal epithelium. He holds a theory that the 
pronephros extends in rudiment, at least, along the entire length of the 
mesonephros, and that this pronephric rudiment develops into the 
adrenal body. He considers the dorsal branches spoken of above, to be 
these vestiges of the pronephros. 
Semper, 75, gives the most interesting account of the rete in the male 
of Acanthias. According to him, each of the 34 primary Malpighian 
corpuscles of the kidney is connected with the body cavity by a peritoneal 
funnel. Seven of the most anterior of these funnels lose their union 
with the peritoneum and take on the form of vesicles. Three or four 
of them now fuse together to form the “ central canal,” which lies at the 
base of the testis and parallel with it. From this central canal there arise 
a number of irregular anastomosing canals which extend into the testis 
and come in contact with the true sex-structures (Vorkeimketten) that 
have arisen from the germinal epithelium. This net-work of rete-cords 
he calls the rete-vasculosum. 
In other forms there exists a somewhat modified condition of consider- 
able interest. In comparing Acanthias and Mustelus, Semper said: 
“ Trotzdem scheint ein grosser Untershied in Bezug auf die Entstehung 
