flO l\ (dM-KlilACK INTKIiWTldWLK W. (.KNKÏInl K. 



Willioul (IouIjI. ir llie cusiomarv conditions in wiiich Ihc organisin oxisls, 

 aller-, tlien llio Lamarckian or Darwinian variations may a|)|)ear, l)ul aKvays 

 with extrême slowness, and l)y nearly imperce[)tible continuons modidcalions. 

 On tlio otlier hand, tlie coalescence or synibiosis of living plasmas must 

 necessarily rcsull in a sndden altération nf llicir Innctions. oi' llicii- |iro(lu<ls. 

 and consequenlly of the exlernal l'orm prodnccd. 



In ISXt). in my article « Sur le mécanmiu' de la vu riitlion dcx rncff; », 

 llnuiiiKiiir II Çlirvreul (Alcan, pnhlisher) I noiiced Ihose al)rn])l modifications 

 oljserved in plants and animais, and explaine<l llicin liy llie coalescence ol' 

 distinct plasmas either by l'erlilization or vegetatively. 



Al Ihat lime, DeVries was beginning Ihose studies on tlie Genus Œ'«o//(('r«, 

 the mutations of which may be reproduced from seed, which were the subject 

 of his celebrated mémoire publishcd five years laler. in 1901. Since that tinie 

 tiie observations of M. Blaringhem and Viguier (1901) on the variations of 

 Cappella bi/rsa pasioris. and other works lately published (Molliard, (laerlner, 

 (Uiarabot et Ebray, etc.), hâve confirmed my observations of 1S7S, liy which 

 I allribuled Iher varions pigments of the Vines to variations of sexual origin. 



ill. The coalescence of végétative or Somalie plasma may be as effective 

 as thaï of germplasm in the production of new races. By such means, not only 

 species but even gênera, may be united. Again, the stimulus lo variation may 

 originale from insects, or from microbes; il may even ad indirectly, as in the 

 case of cerlain mycelia acling on the roots of plants, etc. Il cannot be asser- 

 led that ail modifications that arise in Ihis vvay are capable of transmission by 

 sexual reproduction. Ncverlheless, they do not come under Ihe law of slow 

 and graduai adaptation. 



IV. I conclude that if is by the union or syndiiosis of plasmas, sexual or 

 somatic, resulling from l'erlilization, grafting, or from parasilic or Iraumatic 

 action, Ihal, either modifying the relations of certain ferments, or prevenling 

 Iheir formation, gives rise to Ihose abrupt changes by which new races or new 

 species are produced. The sudden modifications thus caused correspond to 

 Ihose changes in spécifie principles constiluting Ihe new organism as I bave 

 held since 1878. Far from being monstrous. the variations of the individuals 

 and of the races thus formed do not transgress the limils beyond which analogy 

 wilh analomical structures or with spécifie chemical principles no longer exists. 



