PRESENT PKOBLEMS IN EVOLUTION AND HEREDITY. 3 S3 



K'ihot, altliouji'li in the center of tlie French Lnniarckians, says: "Not- 

 witlistandini;' tliese tacts the transmission of aciinircMl inoditicatio'is 

 ajipcjii-s to 1)(» \-ery limited, even wIkmi occuriii^- in both ol" tlie parents." 



lv\cei)ting- from Kolliker; His, the Leipsic anatonust; Ptliiger, the 

 pli,\"sio!ouist : Ziculer, in pathology; and l)e Vries. m hotany, W<'is- 

 maim has not foiiiid mncli sympathy from his own conntrymen in his 

 oi)inion ''that ac(i|Uired characters can not be transmitted; - - 



that there are no i)roofs of such tr;msmission, that its occuirence is 

 theoretically improbable, and that we must attempt to explain the 

 transformation of species without its aid.'"* Besides Virchow t and 

 Einn-r, t llaeckel has expressed himself strongly against VVeismann. 

 My colleague. Prof. Wilson, writes me (.Alunich, Decembcn' 31, 1S!>1) 

 that, while W'eismann's modiiitd theories as to the phenomena in the 

 reproductive cells are pretty generally accepted, Hertwig, Hofer, Paully, 

 lioveri, and others are pronounced advocates of the acquired-charac- 

 ter-transmission theory. 



In l*aiis Brown-Seqnard, who v>as among the lirst to test this prob- 

 lem experimentally by observing the inheritance of the ctfects of nerve, 

 lesions, his assistant, ])upuy, (iiard, Duval, Blanchard, and others are 

 on the affirmative, or Lamarckian side. 



Physiologists generally have fought shy of the <{uestion, although I 

 thinlc in the end they will be forced to take it up with the mor])holo 

 gists, and give us the physio-mor])hological theory of heredity of the 

 future. Prof. Michael Foster, of Cambridge, and Prof Burdon-San- 

 dersoii. of Oxford, l)otli write me that the question has hardly come 

 into the i»hysiologica! stage of inquiry at all. Yet in England Weis- 

 mann has found his strongest su])porters among some of the naturalists : 

 Wallace, Laid<ester, Thiselton Dyer, Meldohi, Poulton, Howes, and 

 othei's; while, cxcei)ting W'indle, tlie anntonn'sts, including Mixart and 

 Lawson Tait, with Sir William Turner as the most prominent, nn^ all 

 Lamarckians. Huxley, Pomanes, and Flower are said to be doubtful. 

 In this country the opinion of naturalists is directly the outgrowth of 

 the <'lass of studies in which each hapi)ens to be engaged. So f;ir as [ 

 know every vertebrate and inverte1)rate pahcontologist is a^ Laniarck- 

 ian,§ lor in this lield all e\(>Iution seems to follow the lines of inherited 

 use and disuse: most of those engaged upon inveitebrat(» zoology in- 

 cline to follow \\'cismaiin. 1 have conversed upon this subject with 

 many ])hysicians, and find that without excejjtion t he t ransmission ol 

 acquired (diameters is an accepted fact among the profession. 



Exact .statement of the prolflrni. — It is important at the outset to 



* liioloffixrlHH (Jeutriilblnll, 18SS, |))>. (jf) iiiul !t7. 

 t I'eber dm Triiiisfoniiisiim.s, Archivf. Anthropolof/ic, '[HH'.), p. 1. 



}Or,<rauic Evolution, u))oii tlui Lawol' luheritanc.o of Aciiinrcd Cli.nactcrs. Tiihin- 

 gcii, 18SS. Tians. 



\N Soc tlll^ writiiijisof Hyatt, Cope, Jkvdcr, Dall, Scott, and others. 



