Physiology of Animals. 63 



in the component cells. Perhaps one might say that 

 the suggestion was, that the cell was in organic pro- 

 cesses like the molecule in the inorganic world. 



The investigation of the structure of cells soon out- 

 ran the physiological interpretation of that structure; 

 for it must be universally confessed that a group of 

 cells in a ganglion, or a digestive gland, or a kidney 

 performs functions which we are often quite unable to 

 connect in any luminous way with the known facts about 

 their organization or mutual relations. On the one 

 hand, we see complexities of cell-structure whose mean- 

 ing is unknown or uncertain; on the other hand, we 

 observe functions which we cannot correlate with any 

 known organization. 



This double break-down has led many to adhere to 

 Huxley's statement (1853), "The cells are no more the 

 producers of the vital phenomena than the shells scat- 

 tered along the sea-beach are the instruments by which 

 the gravitative force of the moon acts upon the ocean. 

 Like these, the cells mark only where the vital tides 

 have been, and how they have acted." 



On the other hand, if we avoid word-quibbles, and 

 define the cell as a unit area of living matter (cyto- 

 plasm and nucleoplasm) ; if we study the phenomena of 

 cell-life in that natural analysis which is afforded us 

 by the unicellular organisms; if we carefully estimate 

 what is known as to complex internal organization of 

 cells and its changes with change of function and ex- 

 ternal conditions ; we may perhaps advance to a more 

 hopeful position that cellular physiology is rather 

 beginning than ended. 



Although we do not know the whole meaning of the 

 nucleus, we know from the experiments of Balbiani, 

 Gruber, Bruno Hofer, Verworn, and others, that a 

 maintenance of the inter-relations between nucleoplasm 

 and cytoplasm is essential to the continuance of cell-life. 

 We cannot explain the activity of the nerve-cells, but 

 the discovery of their dendritic ramifications and extra- 

 ordinary complication of inter-relations has some mean- 

 ing to us. Or, again, that an exhausted nerve-cell 

 should show more or less nuclear collapse (Hodge, 



