298 The Microscope. 



in accord with those of others that are unmistakably of the animal 

 series. 



3. Its contractile vesicle is an attribute peculiar to the micro- 

 scopic animal. True, a similar endowment has been attributed to 

 species of protophyta. I am not convinced that such exist, at 

 least, of the nature and action of those of creatures similar to 

 heteromita. 



4. When the motions and behavior of these mites are 

 taken into account, one receives an impression that they are guided 

 by intelligence and a conscious state wholly different from the 

 influences controlling the motions of the one-celled plants. While 

 this is not a high order of proof, it should not be wholly dis- 

 regarded. It certainly is in constant and instinctive use by those 

 who study these forms. 



Heteromita is clearly an animal. How stands the matter with 

 the lowest plasmodic beings? The amceba, e. g.. has no definite 

 form, its exterior bounding parts are less differentiated than those 

 of the animal described above. It has no specialized organs of 

 locomotion like this one, while it has a nucleus and contracting or 

 pulsating vacuole; it feeds, also, on organic particles which it takes 

 in the solid state indifferently at any part of its body ; and it moves 

 about with a freedom and conscious direction that stamp it as one 

 of the animal series. The very small amoeba found in our creeks 

 and ponds could not well be less complex and still exhibit the 

 functions of animal life. Dr. Carpenter's often quoted words 

 characterizing the rhizopoda aptly describe it: "A little particle of 

 apparently homogeneous jelly, changing itself into a greater variety 

 of forms than the fabled Proteus, laying hold of its food without 

 members, swallowing it without a mouth, digesting it without a 

 stomach, moving from place to place without muscles, and feeling 

 without nerves." But there are lower animals, it is said, the 

 monera, for example: "An organism without organs, which consists 

 of a freely movable, naked body, composed of a structureless and 

 homogeneous sp-rcocle, never differentiating nuclei within the 

 homogeneous protoplasm." Is this existence plant or animal? 

 For one, I am willing to leave it in "No man's land." A large 

 number of the simplest forms once regarded as non-nucleated and 

 without differentiation are on further study found to be nucleated 

 and otherwise not so simple as at first supposed. Monera, it seems, 

 is already limited, and may vanish entirely under the searching 

 scrutiny of recent methods. 



