72 



NATURE 



[March i6, 191 i 



iiillv 



■,,1,,1 



1 ) 



I Mill' 111' ii'illj^ cillli-iriHi- (Ml uniin \\< 



111 I 11 IuiiImi «Miiphasis<-tl by rr<;itiii>^ a 

 stpauiU' .\ vmplialid Mib-farnil\ , ili<- Ilhuiniina' nr 

 Nf(»lr(){)iii;f, fur the lar^^cr ;,T<)iip, tin- ' Daiiaoid Iffli- 



I I hvnJni 

 I ) . 1 n . 1 1 n a ■ 

 \lnil. r 1. 



■!■ lIHIll il>lll(| (111 p. iS 

 111! lil' l.ill'l ^^illlls i^ 



|^7'l ; 



ih. 



li i> 



.:i!i.n. 



an.i // 



I.I.I 

 il A I 111 I I 



u 1: <l . 

 p.ii.i:;i 



I ;i.- I -^iwii- .mil I 1 1 "I - III 



.i|ih arc, ill i\\ cvii'. (OIK (1 iii'd 

 ■ 111 liiilli illiis. aiK.l (In iiol ;;rcall\' 

 I wiiik oil .Mi'iian l\ln>))ali iccra. 

 iiiiiiU an- (liar ami ci uuincinj^", 

 iiUiiialc Milijii'i will) -real skill. 

 (i| ria>iiiniii; i>. li(iU(A"cr, (i|)<.'n 



aiill; 



tmidi siicii; 



l)Cl \\ (I'll il 



ihi^ ami ilii 



w i 1 1 1 1 1 < 



atti I I ihc \ah 



I'hr aulhni' 



and he liaiidli 

 The follduini 

 to rritici^ni. 



S|iiMkiii- III tin- liinair (i| llii- Orii-nla] \ri;y>inis 

 livf^rrhii(\. whiiii, (i\cr in arh llic wlmlc area nf iK 

 tlis(ril)iili()ii, iniinics />. t i:i y.\i pj^us. hul in Au^^lralia 

 rt'seiiiblcs il-- own mail-, and i> iKui-iniincl ic, ihc authdi' 

 concludes : 



" Since il lias hccdinc cstahlislicd in Aiisiralia before 

 the ailM'iil (il ilic Danainc, iniinicry ot the latter is 

 iiniU'(i-<-ai \ fill' iis ciintimiance." 



W't are not convinced that this reasoning' is sound, 

 li may well be that the representative of D. chrysippus 

 has not existed in Australia for a sufficient length of 

 time for the ininiicry to have originated; but the above 

 .ni^niiHiit seems to imply that a u-ell-established in- 

 dii^t nnus form would never be influenced by an 

 i availing model. There is good evidence that such a 

 ehaiii^c is ultimately wrought, as we see in the effect 

 of Ihc Old World Danaidas upon the North American 

 I .i))icitilis ( luisilarchi(i), and of the Oriental Tirumalas 

 {Mi-liii(l(i] upon the Iuhio])ian Papilios, so beautifullv 

 illustiaiicl liy Mr. i;itringham on plate iv of the 

 present work. If these Danaines had not invaded the 

 areas of which we s|)cak, tlicr(.' is little doubt 

 thai the species of l.iittciiitis and Papilio would be 

 still living, but of course without their present mimetic 

 patterns. \ certain avera.ge proportion of destruction 

 take- place in every generation. The advent of a 

 dominant Danaine model does not necessarih' alter 

 this proportion numerically, but affects its (Quality. 

 Whereas \a.riations in the direction of the model 

 were previously (.listribuled at random among 

 the eliminated and the survivors, they now tend, in 

 each generation, to be more thinly scattered in the 

 former set, more thickly in the latter. And the same 

 conclusion holds for every step by vi-hich an elaborate 

 likeness is finally produced. 



The above considerations doubtless supplv at least 

 in part an interpretation of polymorphism in mimicry 

 — the fact that a single mimicking species often 

 appears in two or more quite difTerent forms resem- 

 bling different models. For when- by tlie spread of 

 either itself or the mimic — a new and dominant 

 model. A, comes into relationship with the mimic of 

 an older model, B, the same conclusion holds. The 

 NO. 2159, VOL. 86] 



ii'ii( w ill now for the 



ic >.iir \ i\ ii.:^ proj)ortiofi 



e I i m i ri . 

 tirsl lii; 



mor' , ' and aftej 



a lime Hi' iiiiiii.i ill,.. 1' -■ iiiiM- ,."111 .'\ ,iiiu IJ. Often 

 bill b\ no me.iiis alw.is-, •"Ucb a jirocess is tTannitional 

 .itlordiiiL; il 'deh ill' mimic fin.'illy com* 



to resfinbli at of its range, and B i; 



aiiothi r. .\ ^ood exaiiijjh is to be found in the femal< 

 of AmifLi ttlriiip(:i tangled problem most skilfutl] 

 uni.ivi lied 1)\ .Mr. ICItringham not many months ago 

 The usual wi sierii female of this species mimics th« 

 comiiion paii'iii 'it the ue^icrn male Planemas 

 b'lirihei ' ■ ' •• I'.ntelilie, ihis ji.iftern. although i 

 occur-. mean- domin.'int. and the ordinar} 



form III !• :;i,ii. ,(/i r ' '■ - the male of I'latientt 



»utL(irist(i. and both /'. Poggei. But ran 



examples of the wcso in miniic .are still to be fount 

 among the ali-i"pr fi males at Entebbe, and of th< 

 eastern mimic mi ceri.iin jj.arts of the west coast 

 The probabilit\ tiiat tiie vounger mimetic pattern 

 almost ceriainK the i a-n-rn ha- lieen reached througl 

 dimor|jhism, i- exirenu 1\ strong. 



The author allude- to ihi- deejdy inlcrisiin^^ -ubjer 

 of |)ol\ niorphism in mimier\' - shown ' lecen 



researches of |)r. Karl Jordan to co\ • wide 



are.a than h.is been hitherto supposed- — and infers oi 

 |)|j. (ij, d", ihai till iinly interpretation is to be found ii 

 Bates's hvpDlhesl- of a palatable mimic rcsembrmj 

 a distasteful model : 



"We are forced ... to the conclusion that specie 

 which in the same locality produce polymorph! 

 mimetic forms are Batesian mimics, and that the valu 

 of the multiple varieties lies in the distribution of th 

 mimetic forms ,imoni.;>t a corresponding number o 

 models, thus avoiding the risk of the edible niimi 

 becoming more numerous than its distasteful model 

 a state of things which would lead to a disastrou 

 increase in the amount of e.xperimental tasting 1 

 insectivorous animals."' 



In other |)arts of his work the author himself ci impel 

 us to doiibt the cogency of this reasoning, for h 

 figures and dt scribis such polymorphic mimics amon 

 the higlily distasti ful .\cr;eas -for instance, .4. jodiittt 

 with its two forms of female at Entebbe, and th 

 wonderful series of mimetic patterns exhibited b 

 .4. jolDistdiii in British and (ierman Kast .\frica. 



There are a few t\ jjographical errors, such i 

 " survivials " on p. 2\. which we should scarcelv ha\ 

 expected in a btxik produced by the Oxford L'niversii 

 Press, and should ;dso h.ave anticipated that its exec 

 lent readers would have directed the attention of tl 

 author to an aw kw ard slip in the construction on I. 

 from the bottom of p. 7S. as also to a few ""spl 

 infinitives " scattered through the pages. 



The abundant names of species and genera ha" 

 been very accurately i)rinted. We notice only a sing 

 error — Pscuihtbazis for PscmloJiazis. on p. 118. .\mor 

 names of persons (ruiUt-nic is j)rinted for Guillcmi. 



Mr. Eltringham's monograph is the first attem 

 to set forth .a nearly full account of mimicrv in tl 

 butterflies of one of the great tro])ical regions, 

 has very wisely selected Africa for his purpose. 

 examples are far more numerous and perfect th; 

 j those of the Oriental region ; yet they are manageal: 



