ii2 SCIENCE PROGRESS. 



the unit so separated has from the time of its separation an 

 independent individuality and eventually reproduces the 

 aggregate. The fact that the union of two cells is commonly 

 necessary for the maintenance of life and the exhibition of 

 the powers of development, need not be urged as an objec- 

 tion to this simple statement of the case, for the facts of 

 parthenogenesis show that the union of two cells is not an 

 essential feature. Now if we adopt Wiesner's scheme, and 

 imagine that organisation does not stop at the cell, but that 

 beyond this there are granules, and beyond these again 

 plasomes, and that the plasomes stand in the same relation 

 to the cell that the cell stands to the multicellular organism ; 

 we should expect to find that in the reproduction of 

 monocytial organisms the plasome plays a part anal- 

 ogous to that played by the cell in the reproductive 

 processes of polycytial organisms. But we find nothing 

 of the kind. The monocytial organism reproduces itself in 

 just the same way as the polycytial, by the separation of a 

 cell, complete in all its parts. There is no such thing 

 known, even in cases where a flagellate or a radiolarian 

 breaks up into innumerable particles or spores of extreme 

 minuteness, as the separation of any one individual con- 

 stituent of a cell possessed of the power of leading an in- 

 dependent existence and in time of reproducing all the other 

 constituents. Every spore, however minute, has its portion of 

 the cytoplasm and its share of nuclear matter. If there are 

 any other constituents, it probably has its share of these 

 also, but one cannot speak with certainty on this point, for 

 positive evidence is wofully deficient. At any rate Wiesner, 

 holding fast to his theory that nothing, not even an amylum 

 or an aleurone grain, is produced neogenetically, is at great 

 pains to prove that in cellular reproduction all the parts 

 of the parent are transferred to the offspring. Assuming 

 that this is so, and remembering that there is abundant 

 evidence that nuclear matter and cytoplasm are always 

 transferred, it is evident that the relation in which the 

 plasomes or biophors, regarded as ultimate vital units, 

 stand to the cell, is not at all the same as the relation in 

 which the cell, regarded as an ultimate unit, stands to the 



