178 The Development of the Interstitial Cells of Leydig 



periphery, especially on the side opposite to the nucleus, the cytoplasm 

 is extremely vacuolated. Some of the vacuoles may be spherical with 

 smooth boundaries, biit many of them are irregular in shape with ragged 

 margins, due to projecting strands of cytoplasm. The vacuoles contain 

 no visible substance in material fixed with Zenker's fluid. Their form 

 alone would almost warrant the conclusion that they are not f at-vacuoles, 

 and the special tests with osmic acid and Sudan III furnish no evidence 

 of fat in them. Cells containing acidophile granules of about the size 

 of the eosinophile granules of certain leucocytes are of not very rare 

 occurrence (^ in Fig. 8) ; they are situated in the condensed cytoplasm 

 of the vicinity of the nucleus. Columns of cells are often separated by 

 wide empty spaces, the reticulum is loosened, and one gets the impres- 

 sion that in life the tissue must have been bathed in fluid. The histo- 

 logical appearances suggest a condition, not of degeneration, but rather 

 of active metabolism; the cells which were so greatly atrophied in the 

 pig of 20 cm. have entered here upon a phase marked by increase both 

 of size and of physiological activity. It should be stated here that I 

 was not able to demonstrate mitoses in the Leydig's cells of pigs longer 

 than 7 cm., nor could I feel sure that they multiply by direct division; 

 so that I shall have to leave open the question whether or not new Ley- 

 dig's cells are formed in the later stages by cell-division. I do not think, 

 however, that there is any doubt but that the atrophied cells found in 

 the pig of 30 cm. are quite able to develop into the large cells of the pig at 

 28 cm. ; for the steps of the process can easily be followed in a series 

 of embryos. In this connection we may recall the finding of Hansemann 

 (loc. cit.) in the marmot. 



Ohservations on the Centrospltcres. — In the early stages Leydig's cells 

 present two structures in their cytoplasm with great regularity and con- 

 stancy (Fig. 9). One of them (C. A. in the 



r- -Q figure) is a large sphere, containing a small 



I body at or near its center, from which delicate 



f;^'*^^ radiations proceed toward the periphery of the 



-' •-''"^%fcl^°"' sphere. This periphery is formed by small 



granules in a row. The sphere is alwa3's sit- 



r ^ uated in the immediate neighborhood of the 



Fig. n. Pig 27 mm. Two uucleus, somctimcs at an indentation in the 



trosphere B; c.a', centres- uucleus. The second structure (C. B. in the 



sphere A ; Mallory's con- f» s . , j • • i. ^ 



nective-tissue stain. X 800. figure) IS also a Sphere, containing a central 



body, but it differs from the first structure 



in several particulars. The sphere is smaller, but the central body is 



many times larger than that of the first structure. With the highest 



