564; EIIRENBERG ON THE ORIGIN OF ORGANIC MATTER 



their living motions all the while continuing ; and I searched for 

 analogies in the Coccus, in which the death of the mother takes place 

 before the young ones break the egg, and in the tape-worms ( Tcenia), 

 the hinder parts of whose body separate after, or even at the produc- 

 tion, while the anterior part continues to live. Finally, I established 

 and found in these minute infusoria a fourfold mode of reproduction : 

 by eggs, gemmation, transverse separation, longitudinal separation ; 

 while in the wheel-animalcules, only eggs, or living young from egga, 

 are produced. The smallest Monads observed by me, which yet exhi- 

 bited internal organs of nutrition evidently filled, were g^Vo ^^"" ^" 

 diameter. These measurements are made with a glass-micrometer, by 

 Dollond, which indicates to the -^ishoQ ^^ ^" inch. The granules of the 

 ovarium of those minute infusoria which were observed to produce 

 young, were in their relative magnitude to the mother animal in the 

 proportion of 40 to 1, or as 80 to 1. The eggs of the wheel-animalcules 

 were in general as 3 or 4 to 1 . 



In this way, and by the means which I have stated, I was enabled to esta- 

 blish at once the doctrine of the infusorial animalcules more completely 

 and accurately than it had been up to that time ; and the easily visible 

 colouring of the nutritive organs, from the transparency of these bodies, 

 might well induce others to participate in the results obtained. This 

 elucidation of the infusorial world I gave in an academical memoir 

 read in Berlin, and have circulated since 18.'50 about one hundred 

 copies by the booksellers. The separate copies have the distinct title 

 Organisation, Systematik und geographisches Verhdltniss der Infu- 

 sionsthierchen, V071 C, G. Ehrenberg ; Berlin, 1830. In this folio work, 

 which is accompanied by eight copper plates, I separated the so-called 

 infusorial animalcules, according to their organization, into two quite 

 distinct classes, one of which is distinguished by the great number of 

 ventral cells, and to which on that account I have given the name of 

 ventral animalcules or many-bellied infusoria {Polygastricci) ; the other, 

 which is distinguished by wheel organs and a simple intestine, I have 

 called wheel-animalcules (^Rotatoria). The whole of the results of my 

 observations which I have there given are included in the following 

 fifteen positions : 



1. All infusoria are organized and in part, probably all, highly or- 

 ganized animals. 



2. The infusoria form two quite natural classes according to their 

 structure ; can be separated scientifically according to their structure ; 

 and permit no identification of their forms with greater animals, how- 

 ever similar they often may appear. 



3. The existence of infusoria in the four quarters of the globe and 

 in the sea has been proved ; and they form the chief number, perhaps 

 the chief mass, of animal organisms endued a\ ith life on the earth. 



