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into the histiogenesis of the ovary. The excellent researches of Corrr 
(Acad. Dissertation, Leiden 1898) and of von Winiwarter (Archives 
de Biologie, Tome XVII, 1900) may be mentioned here. As not all 
the embryological textbooks give the same representation of the 
development, I follow the report, which Bünrer gives in Hurtwie’s 
Handbuch (1906). 
The ovary develops like the testis, from a special part of the 
posterior coelomic wall, in which the epithelium proliferates and 
forms a ridge (the so-called Genital-leiste or genital ridge). The line 
of demarcation between the epithelium of the ridge and the embry- 
onic connective tissue is vague. The sexual cells become visible 
afterwards in the epithelium. Generally the line of demarcation 
between epithelium and mesenchyme becomes also clearer. It is 
irregular. The epithelium penetrates actually with fringe-like ingrowths 
into the mesenchyme. Those ingrowths are called “epithelial cords’ 
(ALLEN calls them sex-cords). Sexual cells occur in these epithelial 
cords by the side of undifferentiated epithelium cells. An epithelial 
proliferation arises from the cranial part of the genital ridge, growing 
soon inwardly. Corr calls this mass the “reteblastem’’. When after- 
wards the genital ridge is tied off more and more, a small body, 
hanging on the posterior coelomic wall, originates (the undifferentiated 
sexual gland). There, where it is still connected with the backwall 
of the coelome, the ‘“‘reteblastem” lies, from which a number of 
cords arise, which grow into the direction of the pronephros, as well 
as towards the centre of the sexual gland (rete cords). The sexual 
gland consists of a cortical layer, which is nothing but the epithelium 
of the genital ridge (Str. germinativum or epithelial layer) and an 
inner mesenchyme mass (Str. medullare). The germinal cords penetrate 
from the cortical layer into the Str. medullare. Sexual cells occur 
in the so-called rete-cords and especially in the germinal cords. 
From this stage of development differentiation occurs between the 
development of the male and the female sexual gland. 
The convoluted seminiferous tubules arise from the germinal cords, 
during the development of the testis, the tubules of the rete testis 
from the rete cords. 
During the development of the ovary a thin layer of connective 
tissue (primary tunica albuginea) is formed between the cortical and 
the medullary layer. This tunica albuginea lets the epithelial cords 
pass at many places. A lumen is found, specially in the rete cords, 
less often in the germinal cords. The rete cords are also connected 
with the duct of the pronephros. Processes of development occur 
here, quite homologous to those, taking place in the testis. In the 
