INFUSORIAL ANIMALS. 57 
The infusoria reproduce each other in different ways. First, 
there is spontancous division, technically called fisstparism, or fission. 
By this process the animal divides itself into two equal parts, each 
part becoming an exact resemblance of the original and primitive 
individual, so that literally the child is half its mother, and 
the grandson a quarter of its grandfather! A second mode is 
by gemme, or budding, something after the manner of plants, 
or perhaps more like the emission of an egg which in due 
time develops into an adult animalcule. Who can imagine the 
size of such an egg? Both these processes may be watched 
PROPAGATION OF AN INFUSORE BY SPONTANEOUS DIVISION, OR FISSIPARISM. 
going on in sea water, by any one who has patience enough. 
The whole operation is completed in a very short space of 
time. Very lately it has been discovered that there is a dif- 
ference between the male and female infusore, and this is the origin 
of a third mode of reproduction. Two of the animalcules in the 
course of their wandering through their liquid world—a drop of 
water—meet each other. By some strange force they become 
attached by their anteriors (PlateIII., fig.1), gradually they be- 
come fused into each other (figs. 2, 3, 4,5), and at last appear 
one homogeneous mass (fig. 6). This then becomes surrounded 
by a transparent envelope, and in the interior of the mass four 
nebulous points begin to appear (fig. 7). These gradually extend 
until the whole is divided into four egg-shaped bodies (fig. 8). Soon 
