11. K. M.OMl. WKIATKI.N WIDNG TIIK I! ATS OF IMUA, .'i-Jl 



Uioiigli il cannot bc desfi'iljed brielly, llial Ihis charai'ler is appeaiinj^' sporadi- 

 cally amoiig Indian rais, i.o. in separalc places and aL dill'ercnl limes. Wliole 

 coloured lals lliough usiially producing olTspring likc Ihemselves, occasionaliy 

 aiid undcr some unUnowii intluenco. give birlli lo wliilo-beliied oll'spring. Tlie 

 places and limes oJ' siich unusnal occui'cnces nced nul necessarily be distanl. 

 The iinknown inilucnce inay be local, if so Uie occurenees will be near one 

 anollierin lime and place and llie resulling groiips bcing alike and close loge- 

 llier ai-e likely loamalgamale. The relalion ol'lhe w liile-bellicd rais lo Ihe com- 

 mon kind appears lo be much Ihe same as Ihe relalion of Ihe mulani 73«///(/t( to 

 Ihe common ilecnnlincata, described liy Mr \\'. !.. Tower in his woik upon Ihe 

 polah) lieelles ofAmcrica. Bul ail groiips of like animais arc nol ol' Ihis order, 

 in ni;iuy Ihc means of idcnlificalion consisls of a number of nncorrelaled cha- 

 laeleis For exemple, in Case I Ihe membcrs of Un- group [)ossei-sed al leasl 

 Iwo sucli cliaraclers, mclanism and a peculiar skull form ; in Case ô, Ihe Iwo 

 individuals possessed al leasl four nncorrelaled cliaraclers. 1 believe Ihal 

 groups of Ihis kind do nol originale on more llian one occasion, or Ihat il is 

 exlrendy unlikely Ihat Ihey should arise on more lliau one occasion. Il may 

 lie Uial groups possessing Iwo particular imconclalrd cliaraclers are less 

 likely lo ap[>ear on sevcral occasions llian groups willi one parlicnlar characler, 

 and Ihal groups \\ itli tlircc pniiicular characters arc less likely lo occur repeal- 

 edly Ihan Ihose willi Iwo, and so on. This suggeslion is of course purely 

 assumplive, but il isa fact Ihal each many characlerised group was found only 

 once, whereas each kind of singly-characlerised group occurred and no doubt 

 originaled in many places. 



.Many of ihe groups of verlebrale animais whicli hâve been described as 

 species appear to possess a number of characters which conslilule Iheir marks 

 of i<lentificalion. Thèse cbaraclcrs are, probably for the mosl pari, nncorre- 

 laled, since il bas bcen proved in Ihose domeslic races which bave becn (lie 

 sidijccl ol' breeding experimenls Ihat racial cliaraclers, constiluting marks of 

 idcnlificalion, are nearly always uncorrelated. But liow is il Ihat Ihe same 

 particular collection of iinrorrfl'ilcd c/iafacti'rs appeavs in each of a- very large 

 number of individuals? An answer is, — because ail Ihose individuals are 

 descended from a single individual which was Ihe first to possess Ihal parli- 

 cnlar collection of characters, — MenileFs disco\ery bas shown us thaï a single 

 individual sport of eilher scx may, by crossing wilbthe parent species, give rise 

 lo descendants like ilsclf, but of both sexe.s, in the second génération, and 

 pure Unes of animais bave been raised from single sports found in nature (c. g. 

 by ^^^ L. Tower). The answer given hère bas for me an appearancc of liulh 

 because an alternative can hardly be found, and the cases descrilied aboNc 

 and olheis lik<' lliem support the conclusion. 



h( olijrclliin. — Il is believcd by many Ihal inbicd stock is btuiiid lo dele- 

 riorate sonner or laler. If Ibis is Inie, il is ('\idciil Huit a single animal cannot 

 give rise lo a large group of hcallliy animais of ils o\\ n kind. liul Ihc évidence 

 is by no means conclusive. 



The sirong opinions which arc oficn hcld on Ihis sidijccl are sn|i|ioilcd by 

 Ihe nalural b-eling of humanily agaiii^t inccsl. Ccrlainly il woiild nul lie wcll 

 for liumanily at large if inbrcd sects were to arise among il. Forlunately il 

 ha|ipens Ihat Ihis (pieslion bas been invcstigaled more Iboroughly in the case of 

 rais and iiiice Ihan in anv ollier kind uf animal. W'c kiiow Ihal ha ri ii fui cffecls, 



