200 LIFE AND DEATH. 



on the physico-chemical conditions of the body and 

 the medium. The form depends mainly on physical 

 conditions in the cases of a drop of water falling from 

 a tap, of the liquid meniscus in a narrow tube, of a 

 small navel-shaped mass of mercury on a marble 

 slab, of a drop of oil "emulsioned" in a solution, and 

 of the metal which is hardened by hammering or 

 annealed. In the case of crystals the form depends 

 more on chemical conditions. It is crystallization 

 which has introduced into physics the idea that has 

 now become a kind of postulate namely, that the 

 specific form is connected with the chemical composi- 

 tion. However, it is sufficient to instance the dimor- 

 phism of a simple body, such as sulphur, sometimes 

 prismatic, sometimes octahedric, to realize that sub- 

 stance is only one of the factors of form, and that the 

 physical conditions of the body and of the medium 

 are other factors quite as influential. 



Is the Specific Form a Property of tlie CJiemical 

 Substance ? How much truer this restriction would 

 be if we consider, instead of a given chemical com- 

 pound, an astonishingly complex mixture, such as 

 protoplasm or living matter, or the more complex 

 organism still the cell, the plastid. 



Are there not great differences between the sub- 

 stance of the cellular protoplasm, or cytoplasmic 

 substance, and that of the nucleus? Should we not 

 distinguish in the former the hyaloplasmic substance; 

 the microsomic in the microsomes; the linin between 

 its granulations ; the centrosomic in the centrosome; 

 the archoplasmic in the attraction sphere; not to 

 mention the different leucins, the vacuolar juice, and 

 the various inclusions? And in the nucleus must we 

 not consider the nuclear juice, the substance of the 



