E. H. Whitehead 



173 



spaces, sometimes singly, sometimes in small groups, without any very 

 regular order as regards the other constituents of the testis, except that 

 they are most numerous in the more central intertubular spaces; at this 

 time there are very few, or none at all, immediately under the albuginea. 

 Some of them show mitotic figures. They frequently arrange them- 

 selves along the basement membrane of the tubules. In size and shape 

 they vary greatly (Fig. 2); some are spindle-shaped with the nucleus 

 near the center of the spindle; some are oval with the nucleus in the 

 larger end, while at the opposite end the cytoplasm tapers to a process; 

 some are irregularly oval or spindle-shaped, while others are polygonal 

 with eccentric nuclei. The difference -in size is due principally to vary- 

 ing amounts of cytoplasm. Their nuclei are quite similar to those of 

 the cells which compose the intertubular tissue of the pig of 22 mm. and 

 stil compose the larger part of it in the pig of 24 mm. The nuclei of 

 the Leydig's cells are perhaps larger and more spherical, and may stain 

 more deeply, but in general they are indistinguishable from those of 

 the other cells in the intertubular spaces. The cytoplasm is very gran- 

 ular, and stains well with acid dyes, so that the cells stand out very 

 distinctly. They are markedly branched. In sections stained with 

 hsematoxylin and eosin the cell-margins may appear quite smooth; if 

 Congo-red be employed as the cytoplasmic stain, some notion of the branch- 

 ing may be obtained, but Mallory's method for connective tissue shows the 

 branches best (Fig. 2). The branches 

 vary much as to size. It is difficult, fre- 

 quently, to determine whether they 

 merely interlace with one another or are 

 in actual continuity; in some places, 

 however, the latter relation seems clear 

 enough to justify the conclusion that, at 

 first, Leydig's cells form a syncytium. 

 Figures two and three are taken from 

 rather marked examples of this condition. 

 In addition to thus forming syncytium, 

 some of the processes seem to be con- 

 tinuous with the exoplasmic network of 

 the fixed connective-tissue cells. Thus practically the only difference 

 between the young " interstitial substance " of Leydig and the inter- 

 Liibular tissue of the preceding stage is the greater amount of cytoplasm 

 possessed by the former; even the syncytial arrangement is retained for 

 rt short time. Hence the conclusion is drawn that Leydig's cells are de- 

 rived from the cells of the intertubular tissue, which, as we have seen. 



Fig. 2. Pi<7 2-J mm. A group 

 of young Leydig's cells. Mal- 

 lory's connective-tissue stain. 



X 800. 



