AUTOGENY AND PLASMOGENY, 339 
origin of an organism independent of a parental or pro- 
ducing organism. It is in this sense that on a former 
occasion (p. 183) I mentioned spontaneous generation 
(archigony) as opposed to parental generation or propaga- 
tion (tocogony). In the latter case the organic individual 
arises by a greater or less portion of an already existing 
organism separating itself and growing independently. 
(Gen. Morph. ii. 32.) 
In spontaneous generation, which is often also called 
original generation (generatio spontanea, zequivoca, primaria 
etc,) we must first distinguish two essentially different 
kinds, namely, autogeny and plasmogeny. By autogeny 
we understand the origin of a most simple organic indi- 
vidual in an inorganic formative fluid, that is, in a 
fluid which contains the fundamental substances for the 
composition of the organism dissolved in simple and loose 
combinations (for example, carbonic acid, ammonia, binary 
salts, etc.). On the other hand, we call spontaneous genera- 
tion plasmogeny when the organism arises in an organic 
formative fluid, that is, in a fluid which contains those 
requisite fundamental substances dissolved in the form of 
complicated and fluid combinations of carbon (for example, 
albumen, fat, hydrate of carbon, ete.). (Gen. Morph. i. 174. 
li. 33.) 
Neither the process of autogeny, nor that of plasmogeny, 
has yet been directly observed with perfect certainty. 
In early, and also in more recent times, numerous and 
interesting experiments have been made as to the possibility 
or reality of spontaneous generation. Almost all these 
experiments refer not to autogeny, but to plasmogeny, to the 
origin of an organism out of already formed organic matter. 
