484 J. DUESBERG 



Of the bodies incorporated in the ground-substance, only the 

 chondriosonies, in addition to the centrioles, can be and should 

 be considered of general significance. Chondriosomes are in 

 fact constant and normal constituents of the protoplasm and 

 it is precisely the result, quite expected, by the way, of the 

 present investigations, to show that the structure described in 

 other groups of animals exists also in fishes, and to allow 

 another step toward the demonstration of its ubiquity. The 

 forms of the chondriosomes are various and changeable, though 

 hardly to the extent that one might perhaps be led to believe 

 from the observations of M. R. and W. H. Lewis ('15) on cells 

 in tissue-cultures. To the student of the male germ-cells, for 

 instance, it becomes obvious that these changes in the chondrio- 

 somes are dependent upon certain definite factors and proceed 

 in a definite direction. Of the chemistry of the chondriosomes we 

 begin to have some knowledge : I refer the reader to the valuable 

 summary of that question given by Cowdry ('16, 2) in a recent 

 article. Finally, I am aware that my views in regard to the sig- 

 nificance of chondriiosomes are far from being generally accepted, 

 but I fail to see how anybody could deny the importance of these 

 cytoplasmic constituents. The recent tendency to investigate 

 the problem from the experimental side should, in my opinion, 

 prove very valuable in helping to solve some important aspects 

 of the subject. 



BIBLIOGRAPHY 



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Allen, Ezra 1916 Studies on cell-division in the alliino-rat (AIus norvegi- 

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AuNAP, E. 1913 Ueber die Chondriosomen der Gonocyten bei Knochenfischen. 

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