ON CARYOKINESIS. 18/ 



has no causal connection with the behavior of the archo- 

 plasm, although both tend to accomplish the same end, 

 viz. the formation of two nuclei out of one. It is con- 

 ceivable that one mother coil may sometimes split into 

 two different kinds of substances, and the archoplasmic 

 filaments play simply the part of a distributing agent in 

 carrying these into opposite halves of the dividing cell. 

 In view of the general theoretical conclusion regarding 

 the intimate correlation between form and matter, and 

 mechanism and function, such a view does not appear 

 improbable; for, as has already been stated, the differ- 

 ences of two cells lie in their structure, and the struc- 

 ture being the expression of the chemical substance of 

 the protoplasm which compose them, wherever we find 

 the difference of structure we find difference of sub- 

 stance or substances, and wherever we find difference 

 in the substance, we find difference in property or 

 function. It is probable, as has been mentioned already, 

 that the nuclear substance, by its constant metamor- 

 phoses, gives rise to a series of substances to isolate and 

 distribute which is the function of the spindle, and thus 

 give rise to a number of differently constituted cells. 



In the study of caryokinesis, then, Cytology and 

 Morphology may properly be said to meet ; and the rela- 

 tion which it bears to the broad field of Embryology 

 may not be unlike that which the latter bears to 

 Anatomy. 



If, in conclusion, I recapitulate what has been said in 

 a few words, the cleavage of the ovum may be charac- 

 terized as Analysis of tissues, caryokinesis as the Method, 

 and the archoplasmic spindle as the Instrument. 



