CYTOPLASMIC STRUCTURES IN THE SEMINAL EPITHELIUM OF THE OPOSSUM. 65 



case, as Jordan has endeavored to meet the reproach that his technique may have 

 been defective by saying: 



"Even a poor technique that, however, reveals them (the chondriosomcs) clearly and 

 typically at a certain stage and subsequently, should reveal them at every stage (when 

 present) represented by cells in the same tissue (page 69)." 



It is, in fact, not surprising if Jordan, in his material, could find chondriosomes 

 in the spermatids and not in earlier stages. 



SECOND PERIOD. 



At first the chondriosomes have still a vesicular appearance. Very soon, 

 however, at least in the most peripheric parts of pieces fixed in Benda's or Meves's 

 fluid, they assume the shape of rather large, solid granules (fig. 10). Even this 

 appearance is somewhat artificial and due to a certain amount of swelling, as the 

 granules in the living cell are distinctly smaller. The territory of the caudal tube 

 is entirely free of chondriosomes. Since, in the opossum, the caudal tube fills the 

 whole width of the spermatid, all chondriosomes are separated from the nucleus 

 by the entire length of the tube. In the protoplasmic lobe the chondriosomes do 

 not show any special arrangement; no stage was found during this period as in the 

 guinea-pig (Duesberg, 1910, fig. 46), nor during the preceding period as in the rat 

 (Regaud, 1908), and again as in the guinea-pig (Duesberg, 1910, figs. 57 and 58) 

 in which all the chondriosomes are collected at the periphery of the cell. 



In a somewhat later stage, when the head begins to assume its definite shape 

 (fig. 11), the chondriosomes are constantly found, both in Regaud's and in Benda's 

 material, in groups of thin, bacillus-shaped rods. Still later (fig. 12) they appear as 

 granules, forming several heaps in which the mitochondria are crowded very closely 

 together. The same stage is marked by the first appearance of the so-called "von 

 Ebner's tingierbare Korner" in the form of two or three granules or droplets, which 

 usually are so close together that they fuse, assuming thus a shape different from that 

 of the chondriosomes (fig. 12, upper left corner) . These bodies can be easily distin- 

 guished from the chondriosomes, notwithstanding Jordan's opinion to the contrary. 

 Even after Benda's method, which stains them purple, or iron hematoxylin which 

 stains them black, their shade is different from that of the chondriosomes. Their 

 form is also different. These bodies are fixed by all reagents except Regaud's. 

 They can be brought into evidence in a specific way, even in material in which the 

 chondriosomes are well preserved, by staining the sections with a nuclear stain 

 for example, with safranin. An interesting and convincing experiment consists in 

 unstaining a preparation made with Benda's method after having drawn a given 

 cell and having carefully noted its location by means of the mechanical stage; then 

 staining the preparation with safranin and redrawing the same cell. While the 

 chondriosomes do not take up the safranin, the "tingierbare Korner" do so with 

 great avidity. 



THIRD PERIOD. 



At the time the ring begins to migrate the chondriosomes are still granules, 

 but are scattered all over the cytoplasm (fig. 13). It has already been pointed out 



