BIOPLASM IN DIFFERENT ORGANS AND TISSUES. 49 



moving matter. Amoebae can be obtained for exami- 

 nation by placing a small fragment of animal or vege- 

 table matter in a little water in a wine-glass, and 

 leaving it in the light part of a warm room for a 

 few days. I have found it convenient to introduce 

 a few filaments of cotton wool into the water. The 

 amoebee collect amongst the fibres, which prevent them 

 from being crushed by the pressure of the thin glass 

 cover. The delicate material of which these simple 

 creatures are composed exhibits no indications of 

 actual structure, although it is darker and more 

 granular in some parts than in others. 



96. Bioplasm in different organs and tissues. The 

 bioplasm of all organisms, and of the tissues and 

 organs of each organism, exhibits precisely the same 

 characters. It lives, and grows, and forms in the 

 same way, although the conditions under which the 

 phenomena of life, growth, and formation are carried 

 on differ very much in respect of different kinds of 

 living matter. A temperature at which one kind will 

 live and grow actively will be fatal to many other 

 kinds. So, too, as regards pabulum substances 

 which are appropriated by one form of bioplasm will 

 act as a poison to another. But the way in which 

 the bioplasm moves, divides and subdivides, grows, 

 and undergoes conversion into tissue, is the same in 

 all. Many remarkable differences in the structure, 

 properties, action, and character of the things that 

 are formed are associated with close similarity, if not 

 actual identity, of composition of the matter that 

 forms them. These differences cannot, therefore, be 

 attributed to the properties of the elements, to physical 

 forces, chemical affinities, or to characters which we 

 can ascertain or estimate by physical examination, but 

 they must be referred to a difference in power which is 

 inherited from, pre-existing bioplasm, which we can- 

 not isolate, but which it would be quite unreasonable 

 to ignore. 



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