Tlic Orf/artixm find its Protoplasm 135 



terms introduced the really more significant tiling, namely, 

 that of a definite effort toward a scientific classification 

 of the constituents of the cell, this being based upon and 

 necessitated by the fuller and exacter descriptions of the 

 cell that had been reached. 



This brings us to where we can formulate more closely 

 the question now before us : Do the descriptions fully agreed 

 upon at the present day, of the substances entering into 

 the constitution of living beings, warrant the belief that a 

 single substance, under whatever name, is the basis of life, 

 and is identical for all organisms? No one should fail to 

 notice the two parts of the question: (1) Is there a single 

 substance which is the basis of the whole life of any one 

 organism? (2) If this were answered affirmatively, would 

 that substance be identical for all organisms? 



(a) Cytoplasm and Karyoplasm Differentiated Areas of a 

 Common Basic Substance 



Several competent investigators in this department of 

 biology have summarized both the observational and the 

 interpretative knowledge now in our possession. A liberal 

 appeal to these summaries will furnish a direct and sure 

 answer to the first part of the question, and an indirect 

 though hardly less sure answer to the second part. To be- 

 gin with, I quote from Wilson, the first point to be brought 

 out being that of the relation between the nucleus and the 

 rest of the cell. "Careful study of the nucleus," he says, 

 "during all its phases gives, however, reason to believe that 

 its structural basis is similar to that of the cell-body; and 

 that during the course of cell-division, when the nuclear 

 membrane usually disappears, cytoplasm and karyoplasm 

 come into direct continuity. Even in the resting cell there 

 is good evidence that both the intranuclear and the extra- 

 nuclear material may be structurally continuous with the 



