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LEISURE-TIME STUDIES. 



elusion that sensation, in some degree or other, is an un^ 

 varying concomitant of life, is one which the consideration 

 of the phenomena of animal and plant existence fully en- 

 dorses. But this community of sensation may be more 

 plainly demonstrated if we take a comprehensive glance at 

 the phenomena of sensation and nerve-action as illustrated 

 in an ascending scale, and as we pass from lower to higher 

 confines in each kingdom. One of the most useful animals 

 for purposes of zoological instruction is the Amoeba or 

 "proteus animalcule" (Fig. 47), a creature belonging to 



FIG. 47. Amoebae or "proteus animalcules :" a, Amoeba radlosn^ showing the pro- 

 . trusions of its body-substance; b, Ania'ba diffliicns. The figures represent the 

 same animalcule in different stages of contraction. 



the lowest grade of organisation, and whose body may be 

 accurately described as consisting of a microscopic speck of 

 jelly-like matter && protoplasm of the biologist. To watch 

 an amoeba moving across the field of vision presented by 

 the microscope, by slow contraction of its jelly-like body, 

 and to see it literally flowing from one shape into another 

 (#), is to behold one of the most common and yet most 

 perplexing sights which may meet the biologist's eye. 

 Locked up within this minute speck of protoplasm, in 

 which none of the structures or organs belonging to animal 

 life at large can be discerned, are powers and properties 

 which specially and distinctively characterise the living 

 animal, and which elevate our amoeba, simple as it is, far 

 above all forms of inorganic or lifeless matter. Our animal- 



