252 LAMARCK, HIS LIFE AND WORK 



them germinate, the plant develops all its leaves in 

 the air, and then none of them is divided into capil- 

 lary points, which gives rise to Ranunculus hedcraceus, 

 which botanists regard as a species. 



" Another very striking proof of the effect of a 

 change of circumstances on a plant submitted to it is 

 the following: 



" It is observed that when a tuft oi J uncus bufojiius 

 grows very near the edge of the water in a ditch or 

 marsh this rush then pushes out filiform stems which 

 lie in the water, are there deformed, becoming dis- 

 turbed (tragantes), proliferous, and very different from 

 that of /uncus bufonius which grows out of water. 

 This plant, modified by the circumstances I have just 

 indicated, has been regarded as a distinct species; it is 

 the /uncus sitpinus of Rotte.* 



" I could also give citations to prove that the 

 changes of circumstances relative to organisms neces- 

 sarily change the influences which they undergo on 

 the part of all that which environs them or which 

 acts on them, and so necessarily bring about changes 

 in their size, their shape, their different organs. 



"Then among living beings nature seems to me to 

 offer in an absolute manner only individuals which 

 succeed one another by generation. 



" However, in order to facilitate the study and 

 recognition of these organisms, I give the name of 

 species to every collection of individuals which during 

 a long period resemble each other so much in all their 

 parts that these individuals only present small acci- 

 dental differences which, in plants, _reRroductiori_by 

 seeds causes to disappear. 



" But, besides that at the end of a long period the 

 totality of individuals of such a species change as 

 the circumstances which act on them, those of these 

 individuals which from special causes are transported 



* Crainen junceum , etc. (Moris, hist. 3, sec. 8, t. 9, f. 4). 



