564 EHRENBERG ON THE ORIGIN OF ORGANIC MATTER 
their living motions all the while continuing; and I searched for 
analogies inthe Coccus, in which the death of the mother takes place 
before the young ones break the egg, and in the tape-worms ( Tenia), 
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 eggs, 
are produced. The smallest Monads observed by me, which yet exhi- 
bited internal organs of nutrition evidently filled, were 355 lin. in 
diameter. These measurements are made with a glass-micrometer, by 
Dollond, which indicates to the =5455 of an 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 1830 about one hundred 
copies by the booksellers. The separate copies have the distinct title 
Organisation, Systematik und geographisches Verhdltniss der Infu- 
sionsthierchen, von 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 (Polygastrica); the other, 
which is distinguished by wheel organs and a simple intestine, I have 
called wheel-animaleules (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 with life on the éarth. 
