IV] AND STRUCTURE OF THE CELL 289 



phenomena would be a very great step in philosophy, though the 

 causes of those principles were not yet discovered." The things 

 which we see in the cell are less important than the actions which 

 we recognise in the cell; and these latter we must especially, 

 scrutinise, in the hope of discovering how far they may be attributed 

 to the simple and well-known physical forces, and how far they be 

 relevant or irrelevant to the phenomena which we associate with, 

 and deem essential to, the manifestation of life. It may be that in 

 this way we shall in time draw nigh to the recognition of a specific 

 and ultimate residuum. 



And lacking, as we still do lack, direct knowledge of the 

 actual forces inherent in the cell, we may yet learn something 

 of their distribution, if not also of their nature, from the 

 outward and inward configuration of the cell and from the 

 changes taking place in this configuration; that is to say from 

 the movements of matter, the kinetic phenomena, which the forces 

 in action set up. 



The fact that the germ-cell develops into a very complex structure 

 is no absolute proof that the cell itself is structurally a very com- 

 phcated mechanism : nor yet does it prove, though this is somewhat 

 less obvious, that the forces at work or latent within it are especially 

 numerous and complex. If we blow into a bowl of soapsuds and 

 raise a great mass of many-hued and variously shaped bubbles, if 

 we explode a rocket and watch the regular and beautiful configura- 

 tion of its falhng streamers, if we consider the wonders of a Hmestone 

 cavern which a filtering stream has filled with stalactites, we soon 

 perceive that in all these cases we have begun with an initial system 

 of very slight complexity, whose structure in no way foreshadowed 

 the result, and whose comparatively simple intrinsic forces only 

 play their part by complex interaction with the equally simple 

 forces of the surrounding medium. In an earlier age, men sought 

 for the visible embryo, even for the homunculus, within the repro- 

 ductive cells; and to this day we scrutinise these cells for visible 

 structure, unable to free ourselves from that old doctrine of 

 ' ' pre-f ormation * . " 



Moreover, the microscope seemed to substantiate the idea (which 



* As when Nageli concluded that the organism is, in a certain sense, "vorge- 

 bildet"; Beitr. zur wiss. Botanik, ii, 1860. 



