36 POPULAE ILLUSTRATIONS OF 



The above process is thus described by Dr. Carpenter : " This 

 movement is effected by the protrusion of some part of the periphery 

 of the body into a pseudopodian process of greater or less elongation. 

 Towards this process, and usually for some way into it, there is a 

 current of the internal granular substance ; at the same time there 

 is a retraction of any processes of the like nature which might have 

 been previously put forth from the other side of the body, and a 

 reflux of the granular substance from these towards the centre ; 

 and by a continuance of this change the entire body is gradually 

 advanced in the direction of the new extension." MM. Claparede 

 and Lachmann think it possible there may be an oral aperture, of 

 which the lips might be applied exactly to one another, and only 

 open at the moment of deglutition ; and they support this opinion 

 by asserting positively that there is such an opening in an allied 

 forms to which they have given the name of Podostoma. 



But this singular creature, while it is exactly similar to the figures 

 given above of Amoeba when in repose, has the power of propelling 

 " whiplike filaments " from the end of each footlike process, with 

 which it lashes the water in every direction ; and any animalcule 

 thus caught remains attached to the whiplike filament, which then 

 contracts into a spiral and disappears slowly into the pseudopodium. 

 An appearance something like a mouth is then described, into which 

 the particle of food is now drawn ; but I think the description as 

 given us by Carpenter will certainly apply equally well to the 

 extemporaneous manufacture of a mouth to order, as seen in the 

 true Amoeba ; and certainly, after what we know can be accomplished 

 by sarcode in the Infusoria, and as we shall see by and by in the 

 Sponges, we must not be surprised at its wonderful performances in 

 the Ehizopoda. This remarkable substance, called by Carpenter a 

 "protoplasm," does, in fact, seem to unite within itself some of 

 the powers which, in higher structures, we can demonstrate to 

 depend upon nerves, muscular fibre, organs of circulation, digestion, 

 and even of sense. It is held by many naturalists in the present 

 day, that this " protoplasm" is differentiated in the higher animals 

 into the several organs I have mentioned. 



The first thing that strikes us as remarkable, when looking at a 

 drop of water through the microscope, is the ease and grace with 

 which the animalcules move about. This motion is due, we have 

 seen, to a beautiful series of organs termed cilia. Now these cilia 

 move at a rate which is inconceivable to the faculties of the observer, 

 and they do this under the direct operation of the will of the 

 creature, for they work or remain quiet as it chooses. Here, then, 

 we have motion, and the power of exciting or stopping such motion. 

 But still more remarkable, the next thing we notice is the exercise 



