LAMARCK. 1 5Q 



It seems that the most speculative of all his writino-s 

 were his earlier physical treatises. One of these 

 early works was his Rccherchcs stcr /cs causes dcs 

 principatix faits physiques, written in 1766, ])rc- 

 sented to the Academy in 1780, and published in 

 1 794, (the date of the Zoononiia). Here Lamarck, 

 as we have seen, affirms his belief in the immutability 

 of species and strong disbelief in the theory of the 

 spontaneous origin of life, saying that all the physi- 

 cal forces we know, combined, cannot form a single 

 organic being capable of reproduction. All individ- 

 uals in organic life descend from other individuals 

 altogether similar, which taken together constitute 

 the entire species. It is certain from this that in 

 1766 Lamarck held views similar to those of his 

 master, Buffon, in his third period. It is possible 

 that prior to 1794 his ow^n opinions had become 

 modified, but that he had left his original manu- 

 script unchanged for publication. 



In his Hydrogeologie, published in 1802, he devel- 

 oped his uniformltarlan ideas in Geology and pro- 

 posed the term 'Biology' for the sciences of life. 

 In the same year appeared his Rccherchcs sur F Or- 

 ganisation des Corps Vivants, in which he first 

 sketches out his Evolution theory. This work was 

 particularly upon the origin of the living body, ui)()n 

 the causes of its development, and its progressive 

 composition. It is in the preface of this work that 

 he speaks of projecting a ' Physique Terrestre,' to 

 include three parts : Hydreologie, Mctcorologie, and 



