5'iO l\ COM'KlllvNCK INÏKISWTKiWl.i: liK I.KNK I Inl K. 



Miiimlik'. Now ><iiice Ihc iiuiiibi'r ol' imlividiial^ in ;i spccics is imli'lci- 

 iiiiii:ilc. I liai niinihcr acqu ires iin ;ip|j('iirance ol' immt'iisily, wliiili is faisi- in 

 niauy cases. Il c nrc /innh/ ranf/nml. Ih/d n >:yy/T/rs is an indrirrutiiinlili' 

 nuiilber of li/.e Knimals, su llml irhen irr /hnl II i/rnu/j ti'Ilicli is linii/ril iiinl llii'rr- 

 l'iiri' (Icleriiiinabli' in inimlirr, irr ilrnij llml tliul i/ruujj is a spucii-s. 



Uut lel us l'orgel l'or a inonienl Ihc (■i)nr<'plion ol'speeies ami mn-idii- wIkiI 

 we see in naliiic. The lirsl pari of llie prolilem is, — liow (io aniniaN mi iir al 

 jireseiil as l'e^ariis t;r()Li|)int;'? iVnaiiswer is, — llie\ oceur in "jjroups ol' liKc 

 inilividuals, llie niimher ol' inili\ iiluals in lliese Sifroups varies Iroin Iwo or lliree 

 Io as niany llionsands ul' millions or more. Tlie second pari ol' llie proMi-ni is, 



liow did lliey ediiK' Io he in Ihal slaleV \v\ answer is. - 1Iiioni;Ii a 



proeess ol' coMlrai'lion and expansion, l)ey;innint< and ending in unil\. Nn 



will deny Ihal gronps beconie exlinel liy a |)roeess of eonlraelion or diminnlioii 

 eiiding in. unily and zéro, and no oiie will deny Ihal an eslahlisheil groiip may 

 undergo expansion as well as conlraelictn, hnl Ihere is uncerlainly and disa- 

 greenienl concerning Ihc melhod ol' eslal)lishnienl. 



Many liold, I Ihitik erroneously, Ihal spécifie groups are eslablished hy a 

 pi'oeess ol' eliniinalion which eonies toanend as acreaLive proeess al a niomcnl. 

 which niay Le called Ihe iiioitienl of arrivai ol' Ihe species. The species having 

 arrived may Ihen undergo expansion or eonlraelion. The opinion is, Iiowcver. 

 gaining ground Ihal Ihe monienl of arrivai of a group is Ihe moment of hirlli 

 of Ihe individiial oi- individuals froni v\hieh il gre\\ . 



Eliiiiinnlion. — The facl of eliniinalion is a mosl iniporlanl pari of Ihe 

 Darwinian Iheory. Groiipssland oui from oiie anolher, being very dissimilar 

 in appearance, Ihrougii Ihe exlinclion of inlermediale l'omis. No onc eau deny 

 Ihis of generic gronps and of many of Ihe groups called species w hich origi- 

 naled long ago, bul il does nol seem to bc Irue of ail lliose groups whieh are 

 ealleil species. 



We oflen lind cluslers of closely allied species whith are no doubi of rum- 

 l)aralively recenl origin. Such species arc dislinguishable from one anolher 

 by a few spécial andperhaps inconspicous fcalures, which oflen remind us of 

 Ihe specials (diaraelers of sports. The difl'crenees bclween sueli species may 

 bc so slighl Ihal inlermediale forms are h.ardly imaginable. 



'riœ spurudic occurunce of iji-oups. — \\'e wish Io know whelhcr similar 

 groups (i.e. groups possessing Ihe same spécial characler or eharaclers) origi- 

 nale in se])arale places, al dilTerent limes. This is nol onequeslion bul l\\t>. H 

 musl bc asked separalely of Ihose groups which hâve only one specialeh;;rarler 

 and of those groups which hâve more Ihan one uncorrelaled characler spécial 

 Io Ihem. For exemple, lel us compare (lase -' wilh Cases 1 or ô, Ihe members 

 of Ihe group al Poona each possessed onc obvions characler whieh, being 

 wanling in Iheir immediale neighbours, was spécial Io Ihem and consliluled 

 llieir group mark. This characler may be considered as a wliole l'or il lias nu 

 separale paris: whileness exlending from Ihe ciiin Io llie lail ami sliai)il\ 

 delined from Ihe coloured sides is nol nncommon ainong Indian lals. wliereas 

 whileness of llie abdomen alone or of llie cliin alone is rarcl\ ife\('r seen. A 

 while palcii on llie breasl of an olherwise wliole coloured rai occurs somelimes 

 and ils relation lo Ihe characler of complète albivenlralisni is unknovvii. liul 

 in spile of Ihis we may regard albivenlralisni as one allribiile in Ihe conslilulioii 

 of llic organisni, as an indivisible characler. Now, tliei-e is good évidence. 



