A. IrU'TIRP.. - SCll I.K l'IilNC.II'F DR I.A COALl'SC.KNCE DRS PI.ASM\S MVANÏS. 



ON THE PRINCIPLE OF THE COALESCENCE OF LIVING PLASIWAS AND THE ORIGIN 

 OF RACES AND OF SPECIES 



SU. M MARY 



I. Tlic lliporics of Laniarck or of DaiAvin cxjilaiii llie vai ialion of liviiii^' 

 orK'anisms by their tcndencv lo adapt Ihemsclves lo their surroiindiiigs, and by 

 iiatural scloclion. Bul thèse tlieories seem only to be concerned wilh anato- 

 mical or funclional niodificatioiis, and not willi the traiisforniafion oT 

 substances. They do nol explain those modifications whidi arisc sndilciih . 

 and which aro oflen observed hotli in plants and animais. 



It is knowii Ihat sudden modifications niay •"csult eitlier Irom cross l'eiiiliza- 

 tion, or tVom graffing. Aboul Ihe year t87!t, 1 observed Ihat al Icasl in jilants, 

 variation resulting from cross ferlilization niay modify, nol only the analomical 

 slrucfnre, bnlaiso Ihose spécifie principles which conslitute the new organism. 



lîul similar variations may also resull from the cooptation of somatic 

 plasma. It lias long been observed by horticnllurisls and by Bolanists thaï 

 the sitccitlccharacters oClhegrafl may be Iransferred to Ihe stock. (Bronvaux- 

 medlar, Experimenls of L. Daniel, etc.), and reciprocally, Ihe characlers of the 

 stock to the graft. (Experimenls of Jurie on Vilis Labnisca graftetl by Pouls- 

 sard, and of L. I)aniel on the egg plant or Capsicum grafled on Tomato, etc.) 

 The somatic plasma conlains then a similar proprety lo the germ plasm, viz, 

 the power lo transmit lo the bud, and lo the ovary of the plant, a modification 

 ■which is immedialely apparent, and which, in some cases, may be transmilled 

 to the ofTspring. (AUiaria grafled on (^abbage and Knighis" Pea on Broad 

 Bean, from the seeds of which are obtained plants bearing (lie charaiters of 

 both types I. 



.Mthough more difficult to observe, analogous tacts may be found lo occur 

 in animais: such are the phenomena gronped nnder the lerm lelegonij, and 

 those cases in which inoculation of Ihe ap|)ropriate body renders Ihe organism 

 immune lo the corrcsponding (iisease. 



^^'e may then conclude Ihat when the plasma of a living organism, vege- 

 lable or animal, coalesces with the plasma of anolher species, whelher by 

 ferlilization, vegetalively, or otherwise, a new form, may be produced, the 

 characlers of which may be transmilled to ils offspring. 



II. Whal is the essenlial nature of the variations thus produced? By 

 numerous and minute researches on Ihe pigments of Ihe Vine, in Ihe years 

 I87S-I8S'2, I obtained évidence Ihat, for each modification of the vine, 

 Ihere exisls a corrcsponding spécifie pigment. But I also observed Ihat al 

 though dilfereniialed in their accessory characlers thèse varions pigments 

 possess an analogous chemical structure, and the same gênerai properlies. 

 I made similar observations on the calechins of various Acacias, on Ihe tan- 

 nins, and on various types of chlorophyll, and it must be concluded thaï in 

 plants (and similarly in animais), the slep from one race lo anolher. a fortiori 

 from one species to anolher, causes a modification of the spécifie chemical 

 princi|)les, conslituling the race or species. This chemical difl'erenliation is 

 wilhout doubla sign of a corrcsponding variation in Ihe protoplasm. 



