90 



NATURAL HISTORY 



perform the same important office as members in some 

 of the mammalia ; as the current brings all the particles 

 of matter in the water to the month in regular succession. 

 Thus the little animal, by this admirable design of its all- 

 wise Creator, is enabled to enjoy the choice of its food 

 with as much facility and comfort as the larger animals, 

 refusing such as does not suit its taste, and feeding on 

 that which is more agreeable to it. 



By feeding them on vegetable colouring matter, the 

 polygastric form of their digestive organs is readily distin- 

 guished ; two spherical cavities are shewn in the drawing 

 as filled with opaque matter, and others diaphanous. 



Having given the reader a full account of the mature 

 animalcule, I shall proceed to its mode of propagation. 

 A short time after it has arrived at the form figure 80 in 

 the drawing, it assumes the form figure 79, which repre- 

 sents the same animalcule in the act of casting its spawn, 

 which consists of a loose mass slightly cohering by fine 

 filaments like net- work, as shewn below the parent, in the 

 drawing. The form of the two lobes then becomes very 

 dissimilar and much distorted, as shewn, by the drawing 

 of the same animalcule, at figure 81. It, however, con- 

 tinues to swim about briskly with the others, and whirls 

 like them without any apparent inconvenience. Similar 

 changes in form ensue after each successive spawning, 

 till at last there is little left of the original creature but 

 the anterior lobe, which is diminished in size. 



The spawn remains some time before it exhibits any 

 symptoms of life ; but as soon as it does, and the young 



