BATHYBIUS AND THE M ONERS. 643 



" Monads " occur two microscopic inhabitaBts of fresh water, which in 

 the perfectly simple and structureless constitution of their unnucleated, 

 radiate protoplasmic body resemble Protogenes the genera Protomo- 

 nas {Monas amyli) and Vampyrella (the latter in three dilFerent spe- 

 cies) ; they differ, however, from Protogenes in their mode of propaga- 

 tion. Whereas Protogenes, after it has grown to a certain size, does not 

 gain any further increase of mass, but directly breaks up into two frag- 

 ments, Protomonas and Vampyrella retract their rays, and pass into the 

 inactive state, and meanwhile the little protoplasmic globule becomes 

 encysted, or surrounded with an enveloi^e (cyst). While so encysted, 

 Protomonas breaks up into a great number of smaller globules, and 

 Vampyrella into four fragments (tetraspores). All of these afterward 

 become free, and by a simple process of growth are developed into 

 the perfect form. 



In the mean time I had myself observed, in fresh water at Jena, a 

 fourth allied genus of extremely simple organisms, in all respects like 

 the common Amoeba, but distinguished from it by having no cell-nu- 

 cleus, and no contractile vesicular envelope ; hence I named it Prota- 

 moeha primitlva. While in the first-named three slime-globules (Pro- 

 togenes, Protomonas, and Vampyrella) numerous filaments radiate 

 from the entire surface of the central protoplasmic body, in Prota- 

 moeba, on the contrary, just as in the common Amoeba, there are only 

 a few short, finger-shaped processes, which are constantly changing, 

 being now retracted, and again pushed out in some other place. 

 When Protamoeba has, by taking in food which operation it performs 

 after the manner of Amoeba attained a certain size, it breaks up by 

 division into two parts. I first published my observations of Prota- 

 moeba in the " Generelle Morphologie," vol. i., p. 133. Afterward 

 I published figures of Protamoeba primitiva, which are to be found 

 in my " Natural History of Creation," sixth German edition, p. 167, 

 and in my "Anthropogenic," third edition, p. 414, 



Backed by these observations, which were still further prosecuted 

 afterward by other investigators, and also by myself, I, in 1866, in the 

 " Generelle Morphologie," established a special class, that of Moneres 

 (i. e., simjjle), for all these organisms of most simple constitution, la 

 the first volume of that work I wrote as follows : 



" In order clearly to distinguish from all other organisms made up of hetero- 

 geneous parts these simplest and most imperfect of all organisms, wherein nei- 

 ther the microscope nor chemical reagents can detect any differentiation of tlie 

 homogeneous plasmic body, we give them, once for all, the name of Moneres, or 

 simple organisms. Surely, if we would explain life ; if we would deduce it 

 from falsely so-called ' dead matter ; ' if we would fill up the chasm between 

 organisms and the inorganic world we must needs give special attention to 

 these very interesting but hitherto quite neglected organisms, and lay the great- 

 est stress upon their exceedingly simple morphological constitution, which never- 

 theless is entirely consistent with the discharge of all the essential functions of 

 life. Inasmuch as in these homogeneous living things no trace is to be discov- 



