PLATE '1 



EXPLANATION OF FIGURES 



9 Later stage of hemogenic giant-cell. At opposite poles of the nucleus are 

 located two small, irregular, deeply staining networks, presumably the remnants 

 of the originally single Golgi apparatus. Each moiety of the Golgi net lies 

 peripheral to a cytoplasmic vacuole. The vacuole may have been produced by a 

 contraction of the Golgi nets during dissolution or during fixation. The mito- 

 chondria are exclusively of the minute granular type. Above, in a clearer cir- 

 cular area, the mitochondria are so alined as to simulate varicose and segmenting 

 threads. 



10 Polykaryocyte of the hemogenic series. Several blunt pseudopods occur 

 on this cell. The mitochondria include short rods, granules, and vesicles. 



11 Similar giant-cell with relatively few mitochondria, the majority in the 

 form of vesicles. 



12 Giant-cell from marrow of rabbit, fixed with Carnoy's fluid no. 1 and 

 stained with iron hematoxylin. The cytoplasm contains an anastomosing system 

 of canals, corresponding to the so-called trophospongium of Holmgren. Similar 

 appearances in these cells fixed in the same way were described by Retzius as a 

 Golgi apparatus of the cells. The presumption would seem to be justified that 

 in these cells the 'canals' are fixation artifacts. 



13 a and b Special (amphophil) and eosinophilic granulocyte, respectively, of 

 marrow of the guinea-pig as they appear in Kopsch preparations. Note the 

 similarity of the granules to mitochondria. 



14 a, b and c Primary spermocytes of testis of rabbit, preserved by the Kopsch 

 method. The central nucleus appears as a pale, circular area. The cytoplasm 

 contains a number of granular and bacilFary mitochondria. About the centro- 

 sphere is located a deeply staining network of varicose threads, presumably 

 formed by fusion of rods and granules. In b and c occurs a third structure simu- 

 lating somewhat a smaller Golgi apparatus. It is usually located at the nuclear 

 I)ole opposite to that occupied by the centrosphere and the Golgi apparatus. 

 It may however be located close to the larger network (as in c), and some cells 

 contain two such groups. This third structure is tentatively interpreted here 

 as resulting from the aggregation of mitochondria in certain regions. 



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