AND INORGANIC BODIES. 49 



principle that rules the mineral, in the most highly complicated, 

 than in the most lowly organized beings. 



Doing away, then, with the idea of the necessity of a more or 

 less complicated structure for a medium in which to exhibit the 

 principle of vitality, as distinguished from the inanimate, we can 

 readily imagine that a living being could be possible, were it no 

 more complicated than a drop of water ; and when we come to 

 this conclusion, we have but to call to mind the initiatory stages 

 of the animal, in its egg-form, to realize this thought in its per- 

 fection. 



The most infinitesimal drop of fluid, that is potentially an 

 egg, is as truly so as the most complicated, and likewise as cer- 

 tainly an animate being, as on the day that commences its career 

 as a wanderer over the earth, whether in the waters as a fish, or 

 on land as a quadruped, or in an erect position, a Man. Man or 

 Monad, the mighty oak or the slimy mould of our cellars, are 

 alike the medium for the exhibition of the principle of vitality ; 

 nor can we say how simple that body ought to be which might 

 not be subjected to the dominion of this power. 



But let us return from this digression, and see, if possible, 

 whither the group of Actinophryians will lead us, if we pursue 

 the investigation of the successively higher forms. I will stop 

 but a moment to point out two or three 

 of the characteristic features of one of 

 the Polycystinae, (fig. 23.) a very peculiar 

 group of animals, which stands related 

 to the three groups which I have already 

 discussed ; to the Rhizopods, like Cor- 

 nuspira (fig. 3) and Rotalia (fig. 4), it is 

 allied by its thread-form pseudopodia 

 (fig. 23, ps), which are projected through 

 the apertures of a shell ; to the Sponges 



Fig. 23. Lithocampe tropeziana. J. Miiller. Nat. size, T y (line) long. A 

 mitre-shaped shell enclosing an Actinophrys-like body. Marine, ps, the pseudo- 

 podia projecting in every direction through the pores of the shell. From J. 

 Miiller. 



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