and the other an ascending line or generation of animals." Gros 

 considered the effect of the surrounding environment — tempera- 

 ture, time of year, light, quantity and quality of matter — as 

 the source of heterogenic multiplication O'whims of reproduc- 

 tion") . Gros illustrated his understanding of conversion of 

 types by examples; he discussed the conversion of amoeba into 

 ciliated forms, of euglena into solar forms, while infusoria, 

 in his opinion, are converted into rotifers and sloths. 



The problem of spontaneous development or conception is 

 part of the concept of evolution for Gros, But evolution was 

 not understood by Gros as the arising of live creatures from 

 "chaos and rotten stuff," as many of his predecessors had 

 held. Rather, new forms began as animal -molecules. 



Gros considered the possibility of the conversion of one 

 species into another in an article under the title, "Primary 

 Development of Round Worms, "60 in which he gave examples of 

 metamorphoses, larvae of worms, and also the conception of the 

 infusorian Torquatina from the cells of the mucous membranes 

 of the urinary bladder of frogs. 



The study of the spontaneous conception of parasitic 

 worms in the first third of the nineteenth century reflected 

 the negative effort of the idealistic principles of German 

 Naturphilosophie. It is no accident, therefore, that the 

 supporters of spontaneous generation directly connected the 

 beginning of life with the life power. 



There is no need to stipulate that the study of spontane- 

 ous development of highly organized living creatures, which 

 was widespread at the beginning of the nineteenth century, 

 had nothing in common with Engels 1 materialistic idea of the 

 origin of the living from the non-living. 



The question of the development of living creatures was 

 solved by the supporters of spontaneous generation, and 

 especially A. L. Lovetskii, without the traditional reference 

 to God as creator. It is possible to think that Lovetskii 

 was inclined towards materialism, but the strong root of his 

 opinions was under the obscuring veil of Naturphilosophie. 

 C50) 



60. Gros, "Generation primitive de Nematoides , " BULL. SOC . 

 NAT. MOSCOW (1885), pp. 204 - 226. 



183 



