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, sequivoca, primaria 

 etc,) we must first distinguish two essentially difierent 

 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, etc.). (Gen. Morph. i. 174. 

 ii 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. 



