THE PRESENT POSITION OF CELL-THEORY. 319 



may be claimed for the views which I have put forward. 

 They are founded strictly on the facts, and they do not 

 depend on the assumption of any kind of hypothetical units 

 of which the nature and even the very existence is entirely 

 beyond our ken. 



Since I have not been able to develop my views, I 

 cannot but expect that they will be subject to considerable 

 modification and even to entire overthrow. They form at 

 least an attempt to classify and colligate the various pheno- 

 mena which seem to be germane to the subject, and I have 

 collected and compared a much larger body of facts than I 

 am here able to refer to, without finding any which are 

 contradictory to my ideas. That my ideas are somewhat 

 indistinct need not, at present, be urged as an objection, for 

 indistinctness is not necessarily a sign of falsity. The cell- 

 republic theory was not wanting in distinctness, but 

 it was inappropriate to the facts. I only claim that my 

 ideas are appropriate, and I shall hope to give them more 

 distinctness on a future occasion. 



In the meantime I leave out of consideration a large 

 question, concerning which I think it scarcely possible to 

 give a satisfactory account, in this standing in opposition to 

 Mr. Sedgwick, who thinks that which I have attempted to 

 be impossible, but offers a solution of that which I think 

 scarcely possible. 



The question is, how are we to account for that pheno- 

 menon which I have described as a progress from the state 

 of an independent corpuscle, through a state of many coherent 

 or continuous or conjunct interdependent corpuscles, back 

 again to the state of a single independent corpuscle ? 



Mr. Sedgwick's solution is this : that the unicellular 

 form is assumed by metazoa in order that conjugation may 

 be possible. The single independent corpuscle which re- 

 curs in the cycle is the sexual cell, and the essential feature 

 of sexual reproduction is the conjugation of reproductive 

 cells. The unicellular phase is only assumed in sexual, not 

 in asexual reproduction, and this is to be explained by the 

 consideration that conjugation is as necessary in metazoan 

 life as in protozoan life, but that conjugation between the 



