246 BIOLOGICAL LECTURES. 



nutrition has associated with them, and the meshes of the sim- 

 ple fibres are enlarged as much as the nature and arrangement 

 of their principles will admit." 



Recapitulating, and at the same time reaffirming with some 

 changes, the ideas contained in these chapters (Paling., Part 

 VII, Chap. IV, p. 205), Bonnet says : 



" I was still young when I engaged in those reflections, and 

 I pursued my aim by the glimmer of the facts which I had col- 

 lected and which I compared. The discoveries of Haller on 

 the chick had not then been made, and it is principally those 

 discoveries which have furnished me the most exact knowl- 

 edge, and which, confirming several of my early ideas, have 

 impelled me to penetrate farther into one of the most profound 

 mysteries of nature. 



"/ at first assumed, as a fundamental principle, that nothing 

 was generated ; that everything was originally preformed, and 

 that what we call generation was but the simple development 

 of what preexisted under an invisible form and more or less dif- 

 ferent from that which becomes manifest to our senses. 



" I postulated that all organized bodies derived their origin 

 from a germ which contained tres en petit the elements of all 

 the organic parts. 



" I conceived the elements of the germ as the primordial 

 foundation, on which the nutritive molecules went to work to 

 increase in every direction the dimensions of the parts. 



" I pictured the germ as a network, the elements of which 

 formed the meshes. The nutritive molecules, incorporating 

 themselves into these meshes, tended to enlarge them ; and 

 the ease with which the elements glided over one another 

 permitted them to yield more or less to the secret force that 

 drove the molecules into the meshes and tended to open 

 them. . . . 



" I thus excluded every new formation, admitting only the 

 mediate or immediate effects of a preestablished organism, and 

 endeavoring to show how it could suffice for everything. 



" Strictly speaking, I said (Art. 83, pp. 47, 48), the 

 elements [inorganic] do not form organic bodies ; they only 

 develop them, and this is accomplished by nutrition. The 



