THE BEGINNINGS OF LIFE. 161 



down of one substance is often the necessary step to 

 the formation of another : so that the histolytic or dis- 

 integrative molecules of one period become the histo- 

 genetic or formative molecules of another 1 .' The theory 

 of organization advocated by Prof. Huxley and others is 

 c molecular' from a functional point of view, whilst 

 this of Dr. Hughes Bennett bears principally upon the 

 developmental and structural aspects of the doctrine 2 , 

 although he also distinctly teaches that the vital forces 

 are dependent upon molecules and not upon cells. 

 Speaking of his general doctrine, Dr. Bennett says : 

 c The molecular, therefore, is in no way opposed to a 

 true cell theory of growth, but constitutes a wider 

 generalization, and a broader basis for its operations. 

 Neither does it give any countenance to the doctrine of 

 equivocal or spontaneous generation 3 .' It can scarcely 

 be said that Dr. Bennett has succeeded in convincing 



1 Lectures ' On Molecular Physiology,' &c., ' Lancet,' 1863 ( v l- *) 

 p. 56. 



2 A doctrine of this kind had been previously hinted at by Pineau in 

 1848 (' Annal. des Sciences Naturelles '), when he expressed his belief 

 that the primary phenomenon in the development not only of cells, 

 animal and vegetable, but also of Infusoria, consisted ' essentiellement 

 en une agglomeration des granules.' He described observations by 

 which he had satisfied himself that such a mode of formation occurred 

 in the origin of certain Infusoria, and also in the formation of the spores 

 of certain Lichens. According to Virchow (loc. cit. p. 26), Baumgartner 

 and Arnold had also expressed their belief in a similar mode of origin of 

 tissue elements. 



3 Lectures in 'Lancet,' 1863, p. 4. Lately, however ('Pop. Science 

 Review,' Jan., 1869), Dr. Hughes Bennett has proclaimed his firm 

 belief in the doctrine of ' Spontaneous Generation.' 



M 



