32 J. E. WODSEDALEK. 



bivalent lined up for division in the metaphase stage of this cell 

 and that all but the six in the center had divided. Only two or 

 three of these six remaining undivided could possibly be taken 

 for bivalents, which fact indicates that the bivalents as well as 

 the univalents had divided. The centrosomes were well defined 

 and there were only slight indications of deterioration in the cell. 



The researches of Hansemann ('91), Lustig and Galeotti ('93) 

 and others, show that asymmetrical mitoses are of very general 

 occurrence in carcinoma cells and other pathological tissues; 

 and Schottlander ('88) and Galeotti ('93) among others have 

 shown that similar abnormalities in mitosis may be produced 

 artificially in many tissues by treatment with dilute solutions of 

 various drugs, such as quinine, chloral hydrate, cocaine, potassic 

 iodide and antipyrin. 



At first thought, in view of what is known about the effects 

 of drugs on mitosis, it would appear that the abnormalities in 

 division of the primary spermatocytes are probably due to some 

 deleterious chemical substances which may be produced by the 

 degenerative processes going on in the tubules. This however, 

 does not account for the fact that the abnormalities in the mule 

 are practically entirely restricted to the primary spermatocytes. 

 It appears more certain that the abnormalities in this hybrid are 

 due to the conflicting tendencies brought into action within the 

 cells themselves at this stage of spermatogenesis when cooperation 

 between the two parent plasmas becomes necessary but is 

 impossible on account of their vast dissimilarity. 



GIANT CELLS. 



Giant cells appear occasionally but do not seem to be as 

 numerous as was described by Guyer (*oo) in hybrid pigeons. 

 Fig. 37 represents a large cell of rare occurrence. It appears to 

 be a primary spermatocyte with three spindles in the anaphase 

 stage, but the chromosomes are unusually small and resemble 

 more those of the nurse cells. 



Fig. 38 shows an enormous cell with four large nuclei. The 

 cell is evidently a primary spermatocyte in the early prophase, 

 as the size and structure of the nuclei, and the uniform consist- 

 ency of the cytoplasm are identical to those of normal cells in 



