394 JOHN LEWIS BREMER 



testis tubules on the other. His results, obtained by studying 

 pig and rabbit, I have confirmed, with slight variations in man. 

 Briefly stated, Allen's facts are these; the testis tubules originate 

 as cords of epithelial cells containing germ cells, which grow inward 

 from the peritoneal epithelium covering the middle third of the 

 genital ridge; the rete is formed of similar cords growing inward 

 from the anterior third of the same ridge. Both sets soon lose 

 their attachments to the peritoneum, so as to lie free within the 

 ridge. The rete cords, forming a network, grow into the medias- 

 tinum, extending caudally to reach the inner or central ends of the 

 testis cords, with which they become joined. On their way, the 

 rete cords unite with the glomeruli of the Wolffian body, thus 

 completing the passages by which the products of the seminiferous 

 tubules are later carried away from the gland. The testis cords 

 Allen described as anastomosing and branching, and occasionally 

 growing parallel to the surface. 



Further detailed study of these testis cords gives rather sur- 

 prising results. Instead of branching and anastomosing irregu- 

 larly, as suggested by Allen's description, the cords form a com- 

 plete network, every cord anastomosing with others, leaving no 

 free ends except those at the periphery and those near the medias- 

 tinum. The bases of the cords, at the periphery of the gland, 

 form free ends when they have lost their connection with the 

 peritoneal epithelium from which they grew; and the distal ends 

 of the cords, which, since growth is centripetal, are found near 

 the mediastinum, are also usually free ends, though occasion- 

 ally two may join at their tips. Otherwise all the cords are joined 

 by anastomosing branches. As a whole this network is crescentic 

 in cross section, occupying a peripheral zone of the genital ridge, 

 of which the mediastinum is the eccentric core; this brings the 

 central ends of the cords nearer together, and accounts for the 

 occasional anastomosis of their tips. 



Although this network (fig. 5) seems at first sight to be quite 

 irregular, a more critical study shows that each of the cords has 

 three (occasionally four) sets of branches, so that there are three 

 sets of cross connections joining the radially disposed cords. 

 One set of branches is given off a little distance from the peritoneal 



