COMPARED WITH THOSE OF ANIMALS. 61 



The multiplication of cells by gemmation or budding, 

 and also by division, is seen in animals as well as plants, in 

 the simplest as well as the most complex forms. Thus the 

 whole zoophytic structure is produced by continuous gem- 

 mation from a single OTum, and in the lower articulata, 

 annelida, and reptilia, the parts of the body which have 

 been accidentally lost are speedily reproduced. It is well ' 

 known that crabs and spiders, on losing a limb, acquire a 

 new one. The same happens with the arms of star-fishes. 

 The tail of a lizard is also reproduced. Salamanders re- 

 cover their lost legs, and even the eye, with all its com- 

 plicated parts. These vegetative manifestations are, how- 

 ever, mainly restricted to the lower forms of the animal 

 kingdom ; as animal life becomes more developed, this repa- 

 rative power is proportionably lessened, although we are 

 not without some evidence of it in our own bodies, as when 

 a new skin is formed over a wound, or a broken bone is re- 

 united. 



