2 ZOOLOGY. 



early observers regarded them as " animal flowers ;" and in 

 consequence of the confused notions originally held in regard 

 to them the term Zoophytes has been perpetuated in works 

 on systematic zoology. Even at the present day the com- 

 pound Hydroids, such as the Sertularia, are gathered and 

 pressed as sea-mosses by many persons who are unobservant 

 of their peculiarities, and unaware of the complicated anat- 

 omy of the little animals filling the different leaf-like cells. 

 Sponges until a very late day were regarded by our leading 

 zoologists as plants. The most accomplished naturalists, 

 however, find it impossible to separate by any definite lines 

 the lowest animals and plants. So-called plants, as Bacte- 

 rium, and so-called animals, as Protamcela, or certain mo- 

 nads, which are simple specks of protoplasm, without gen- 

 uine organs, may be referred to either kingdom ; and, in- 

 deed, a number of naturalists, notably Haeckel, relegate 

 to a neutral kingdom (the Protista) certain low- 

 est plants and animals. Even the germs (zo- 

 ospores) of monads like Uvella (Fig. 1), and those 

 of other flagellate infusoria, may be mistaken 

 for the spores of plants ; indeed, the active fla- 

 Pi i -Uvei- grated spores of plants were described as in- 

 in'r J?orian lla or ^ usor ^ a ^7 Ehrenberg ; and there are certain so- 

 monad, with called flagellate infusoria so much like low 



two large ci- . , , ., - _ . 



iia called plants (such as the red snow, or Protococcus), 

 magi in the form, deportment, mode of reproduc- 



tion, and appearance of the spores, that even 

 now it is possible that certain organisms placed among them 

 are plants. It is only by a study of the connecting links 

 between these lowest organisms leading up to what are un- 

 doubted animals or plants that we are enabled to refer these 

 beings to their proper kingdom. 



As a rule, plants have no special organs of digestion or 

 circulation, and nothing approaching to a nervous system. 

 Most plants absorb inorganic food, such as carbonic acid 

 gas, water, nitrate of ammonia, and some phosphates, silica, 

 etc. ; all of these substances being taken up in minute quan- 

 tities. Low fungi live on dead animal matter, and promote 

 the process of putrefaction and decay, but the food of these 



