VITAL PROPERTIES OF PROTOPLASM. 47 



displaying rigidity in any degree, from the softest 

 gelatinous membrane up to the hardest teeth-enamel ; 

 nor to anything exhibiting a trace of .structure to the 

 finest microscope ; nor to any liquid ; nor to any sub- 

 stance capable of true solution. 



Thus "nothing that lives is alive in every part," 

 but as long as any individual part or tissue is properly 

 called living it is only so in virtue of particles of the 

 above-described protoplasm freely distributed among, 

 or interwoven with the textures so closely that there 

 is scarcely any part l-500th of an inch in size but 

 contains its portion of protoplasm. Thus we see 

 realized the hypothesis of Fletcher, that all living action 

 is performed solely by virtue of portions of irritable or 

 living matter interwoven with the otherwise dead 

 textures. According to Beale, " of the matter which 

 constitutes the bodies of man and animals in the fully- 

 formed condition, probably more than four-fifths are 

 in the formed and non-living state. All this was, 

 however, living at an earlier period of existence." 

 This is on an average, for some tissues contain much 

 less living matter; the bones, for example, only l-20th, 

 and some textures, when old, not more than l-100th. 



Vital Properties of Protoplasm. The chief vital 

 properties of the living matter, or bioplasm, are thus 

 described by Beale : " It alone is concerned in develop- 

 ment, and the production of those materials which 

 ultimately take the form of tissue, secretion, or de- 

 posit, as the case may be : and of producing matter 

 like itself out of matters differing materially in com- 

 position, properties, and powers. Upon it all growth, 

 multiplication, conversion, and, in short, life, depend. 



