INFUSORIA. 29 



We feel, therefore, but little surprise that with 

 such powers of propagation, these minute creatures 

 soon become diftused in countless myriads through 

 the waters adapted to their habits. 



Nor is this all: the reproduction of these prolific 

 animals is sometimes effected in various wavs, and 

 not unfrequently the same individual is found to 

 propagate by two or three different modes — thus, 

 many species are multiplied by buds which sprout 

 like those of plants from the surface of tlieir bodies, 

 and speedily attaining the shape of their parent, 

 develop the cilia characteristic of their species. 



Fig, 16.— figure of vagixicola. 



Neither is it difficult to understand the necessity 

 for such amazing fecundity. These moving atoms 

 are the source from which innumerable animals 

 derive their sustenance, which, in their turn, become 

 the prey of creatures higher in the scale of life ; 

 they, therefore, form the basis of that mighty pyramid 

 which bears upon its apex Man himself They are 

 the boundaries between life and death, the steady 

 barrier of the organic world, and although until a few 

 years ago, man was ignorant of their very existence, 

 they have not the less been actively employed since 

 first creation dawned. As individuals, they are weak 

 enough ; but in their countless legions they become, 

 perhaps, the most important agents in the grand 

 economy of nature. A grain of sand is but a de- 



