E. H. Whitehead 169 



Leydig's cells in cat embryos/ using unstained sections of material fixed 

 in Hermann's fluid. He begins his observations with the embryo of 

 seven weeks, which, we may note, is quite a late stage. Here he finds 

 Leydig's cells in all stages of transition to fixed connective-tissue cells, 

 the transition 23roceeding from the neighborhood of the blood vessels 

 towards the seminal tubules. He could find but one Leydig's cell con- 

 taining a mitotic figure. Fat is present only in minute droplets. " In 

 the embryo at term the Leydig's cells are in close apposition with the 

 walls of the tubules, and their nuclei are eccentric in position; drops of 

 fat are present in the portion of the cell-body which lies opposite the 

 nucleus. The subalbugineal layer of Leydig's cells is quite thick. In 

 the newborn cat the subalbugineal layer of cells has almost vanished, 

 owing to the increase in length of the tubules. Fat is wanting in m^py 

 of the cells, which present, therefore, a spongy appearance. He con- 

 cludes that Leydig's cells are developed from the connective tissue which 

 accompanies the blood vessels of the testis, somewhat after the manner 

 of typical fat cells, and regards them as trophic nurse-cells ("trophische 

 Huelfzellen "), whose function is to pass their specific inclusions into 

 the seminal tubules. 



M. V. Lenhossek ^ confirms, in the main, the observations of Eeinke 

 as to the crystalloids. He is inclined to regard the interstitial cells as 

 epithelial. He thinks that the presence of crystalloids in them and 

 the absence of connective-tissue cells elsewhere in the body similar to 

 them are decided evidence against the opinion which classes them with 

 the connective tissues. He advances the theory that they are unused 

 remains of the germinal epithelium, and that their function is to store 

 up pabulum, which they give over on demand to the seminal tubules. 



H. Beissner,' in an article intended mainly as a refutation of the 

 opinions of Plato, calls attention to the work of M. iSTussbaum in 1880. 

 The latter held that the nests and strands of Leydig's cells were invested 

 by a membrane similar to the wall of the seminal tubules, so that one 

 might compare them with the Pflueger's tubules of the ovary. He sug- 

 gested that they were groups of germinal epithelium which had stopped 

 developing at an early stage — a suggestion somewhat like that of v. Len- 

 hossek. 



^ Zur Kenntniss der Anatomie und Physiologie der Geschlechtsorgane. Arch. 

 f. mikr. Anat., Bonn, 1897, Bd. I, p. 640. 



^ Beitraege zur Kenntniss der Zwischenzellen des Hodens. Arch, f . Anat. u. 

 Physiol., Leipzig, 1897, Anat. Abth., p. 65. 



^ Die Zwischenzellen des Hodens und ihre Bedeutung. Arch, f . mikr. Anat., 

 Bonn, 1898, Bd. LI, p. 794. 

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