I 2 2 SPONTANEOUS GENERA TION. 



Ehrenberg. Lamarck, one of the most fervent advocates of heterogeny, 

 in his celebrated 'Philosophic Zoologique' (Paris, 1809), freely declared 

 that all bodies were constantly undergoing mutations of form, some passing 

 continually from the state of the inorganic into the organic, and others 

 reverting from the living to the inanimate condition. Nature was further 

 represented as thus exhibiting one continuous evolutionary cycle, and with 

 the aid of heat, light, moisture, and electricity, as producing new organisms 

 by direct or spontaneous generation at the initial or root terms of both the 

 animal and vegetable kingdoms. 



Almost contemporaneously with this pronunciamento of Lamarck 

 appeared also Lorenz Oken's celebrated * Lehrbuch der Naturphilosophie,' 

 in which, in addition to further expounding his views initiated in the year 

 1805 concerning the fundamental construction of all living bodies out of 

 vesicular or cellular elements that found their equivalents in the inde- 

 pendent and simple vesicular bodies of infusorial animalcules, he declared 

 himself most strongly in favour of " spontaneous generation." Oken's 

 remarkable enunciation of these two separate principles in their mutual 

 or interdependent aspect is thus expressed in the treatise above quoted : 



" The first organic points are vesicles. The organic world has for its basis an 

 infinity of vesicles. The mucous primary vesicle may in a philosophical sense be 

 aptly called an infusorium. If the organic fundamental substance consist oi infusoria, 

 so must the whole organic world originate from infusoria. Plants and animals can 

 only be metamorphoses of infusoria. This being granted, so also must all organiza- 

 tions consist of infusoria, and during their destruction dissolve into the same. 

 Every plant, every animal is converted by maceration into a mucous mass; this 

 putrefies, and the moisture is stocked with infusoria. Putrefaction is nothing else 

 than a division of organisms into infusoria, and reduction of the higher to the 

 primary life. Organisms are a synthesis of infusoria. Their generation is none 

 other than an accumulation of infinitely numerous mucous points or infusoria. In 

 these the organisms have not been at once wholly and perfectly depicted as on the 

 smallest scale, nor contained in a state of performation ; but they are only infusorial 

 vesicles, that by different combinations assume different forms, and grow up into 

 higher organisms. 



" As the whole of nature has been a successive fixation of aether, so is the 

 organic world a successive fixation of infusorial mucous vesicles. The mucus is the 

 aether, the chaos for the organic world. The semen of all animals consists also of 

 infusoria; the same may be said of the vitellus. Every generation commences 

 d priori or from the beginning. The organic substance must again be dissolved 

 into the original chaos or mucus if anything new should originate. Out of an 

 organic menstruum only can a new organism proceed, but not one organism out of 

 the other. A finished or perfect organism cannot gradually transform itself into 

 another. The generative juices, or semen and vitellus, are none other than the 

 total organism reduced to the primary menstruum. Physically regarded also, every 

 individual originates only from the absolute, but no one out of the other. The 

 history of generation is a retrogression into the absolute of the organic, or the 

 organic chaos-mucus, and a new evolution from the same. This development from 

 mucus is only applicable, however, to the generation of the perfect organisms, but 

 not to the origin of the organic body, or the infusorial mass. The former originate 

 only from an organic mass that has been already formed ; but the infusorial mass, as 

 constituting the organic primary bodies, cannot have originated in the same way. 

 It was and must originate directly from the inorganic. From whence can the 

 organic have otherwise proceeded? The infusorial mucus-mass originated at the 



