H^1,man Physiology. ii() 



the microscope have a great variety of organs by which they 

 can move about, seize, entangle, and devour their prey, nourish 

 their systems, and propagate their species. Some have cilise 

 little hairs which move with great velocity, propelling the 

 animal like an engine, or forming little whirlpools which suck 

 their food into their mouths. A bell-shaped animalcule is 

 anchored by a spiral filament which enables it at will to push 

 itself out for food or draw back from danger. Some glide 

 through the water graceful as swans; some roll like wheels; 

 some are provided with long threads which they shoot out 

 suddenly like lassoos. These threads are armed at intervals 

 with sharp spines which carry poison, or have some benumbing 

 influence. 



As if creative life revelled in its own special element water, 

 we find every sort of ingenious mechanism in the sea. The sea 

 mouse is provided with a perfect harpoon with barbs, which is 

 thrown out from a sheath formed to protect it from injury. 

 The actiniae, which, near the surface, are dusky and ugly, and 

 covered with fragments of shell and gravel for protection, in 

 the deep water are naked and beautiful. They have air-vessels 

 to float them, and the power of throwing out such numbers of 

 thread-like feelers, that they resemble skeins of cotton, or 

 flowers. These tentacles are thirty or forty times as long as 

 the sheath into which they are folded, and are armed with 

 poisonous or benumbing spines, or poison darts, which are, in 

 some cases, coiled up like a watch-spring in the tentacula, 

 ready to be thrown out and strike their prey. 



The Globe Baroe is a minute but most wonderful animal, 

 which propels itself by some inconceivable nervous and mus- 

 cular apparatus with paddles like those of a steamer, and 

 throws out long cables from its body, and from these still other 

 branching cables for food or. anchorage. 



Among the 15,000 recognised species of mollusca, there are 

 some furnished with vulture-like heads constantly snapping 



