THE PROTOPLASMA AND THE CELL. 



15 



maintains the old life. This multiplying process was, in 

 old times, badly z 



enough designated 

 " endogenous cell for- 

 mation." Mother and 

 daughter cells were 

 spoken of. The so- 

 called mother cell is 

 nothing but the cell 

 capsule. 



Does the process of 

 division of the human 

 cell take place slowly 

 or rapidly ? We be- 

 lieve the latter ; al- 



Fig. 19. — Diagram of dividing mcapsulated bone cells ; 

 tllOU cr ll a proof Can *■ ce " body; <S capsule; c, nucleus; d, endogenous 

 fc> " cells ; e, supplementary capsule formation. 



scarcely be presented 



here. In the lower animal groups, at all events, processes 



of division occur which are completed with great rapidity. 



We cannot yet leave the process of division, for we now 

 encounter the question : Which constituent of the cell, 

 nucleus, or protoplasm, here assumes the chief role f That a 

 non-nucleated lump of protoplasma is capable of dividing, is 

 shown by the protamceba. It is poss'ble that the nucleus is 

 only passively simultaneously con- 

 stricted, an opinion to which we are 

 inclined. Meanwhile cells which, in 

 the undivided body, present two sep- 

 arated nuclei (Figs. 12, 18, 19), and the 

 multi-nuclear myeloplaxes (Fig. 13), 

 constitute a certain objection. Once 

 more, therefore, uncertainty. 



The blood, lymph, and chyle consist 

 of cells suspended in a large quantity of fluid ; in the blood, 

 as we already know, these bodies are present in enor- 

 mous numbers. Something similar is presented by a 

 pathological product — pus. Should one speak here of tis- 



Fig. 2c. — Simple flattened epi- 

 thelium ; «, of a serous mem- 

 brane ; b, of the vessels. 



