514 i\ (:(im-ki;km;|' inti:ii\atiiinai,k dk cknktimi i:. 



;ils(i i'- llir l'oi'iii (iT llic ^l^nll. 'l'Iicvc |iiiiiil>~ ;iri' ^Ikiwii iii l-'ii;> I ;iiiil '.'. wliich 

 \\<'|-(' ili;i\\ Il rriiiii ^111 ;iiiiiii,'il cii^A iiicil in ( iMiriilla. As n'i^anl-i I lir cnlour ol' llic 

 l'iir. Ilic s|iccii's Is \ci\ \;iii;ililc. \\\ i'iiv llio (•()iiiiiiiiiic--l l,\pi' iii linlia is wholc 

 foloiircil liiowii, liiil Iwo sirikiiiii \,iriolies occiir cmcIi li;i\iiii; a spocial colonr 

 character of ils own. Tliese cliaraclers are niplanisni aiid all^ivoiilralism. 'riic 

 former is wcii linii\\ii:a rai endowcd wilh albivonlralisin is [>uir wliilc a- 

 regards llio l'iir ol tlic cntirc lower surface, of the lower jaw, tlirual. lu-rasl 

 and helly, llie wliilonoss lieing sliarply definod from llie coloiired sides. 



Anollier species wliicli nnis| he menlioncd is Giinoiny^ lien<i(il('n:<i>i. The 

 goniis (iiiDomys is confiiicd lo Asia, lience this species is less generally known 

 llian llie last menlioned. Animais of tliis species havc long Ijeen Unown as 

 liciil rats, burrowing in rural places, but in tlie last few years il bas been noli- 

 ccd llial they live and breed as house-rals, in some of Ihe larger towns. The 

 species was long Unown as Ncsakia henyalcnsia, but the genus Nc!<iil:iii lias 

 recenlly been subdivided (Ann. et Mag, Xat. Hist. 1907) Gitnonrys bcing esta- 

 blished for part of it. They are about the same size as M. ratlus, but more 

 sloutly built and with mucb shorter tails. Figs Ti and i will show by compari- 

 son wilh ligs. I and '2, tiie kind of dilTerenccs which occur between Ibe two 

 species. The colour of the fur is greyish-brown of a darUer tone ihan in rattiis 

 and it is much less variable tban in that species. Albiuo. whole-coloured yel- 

 low, and melanic varieties were seen bul very rarely : wliile-bellied ones werc 

 never found. 



The species Mus ilecumanus which is common in mauy sea-pnil lowiis in 

 the East need nol be menlioned hère. 



T/ii' alinoniiiil k'ni<l^. 



We now come lo the main pari of the subjecl, the description of groups 

 of abnormal inilividuals wbich were found living among a normal comnuinity. 

 The ternis normal and abnormal arc used hère to indicate thaï which is in the 

 majorily and that \\ hich is [in the minorlly. Tlie opportunity of observing an 

 abnormal group can occur bul seldom, siuce sucb an observation inust include 

 a complète knowledge of llie normal species Ihroughout a considérable s|iace, 

 as for example in nearly ail Ihe bouses of a large town: andsecondly. the group 

 of Ihe abnormal kind must bc known from Ihe capture of more tlian a very l'ew 

 individuals wbich are found living in communily. Thèse conditions were besl 

 fulfilled on Iwo occasions, al Rangoon and al Pooiia. 



Cwsc \ (al Rangoon). — I bave already menlioned Ihe large number of ral>- 

 which were being destroyed in this town, niosl of Ihem were brought iii by 

 the lownsfolk for the sake of reward. About one Jiundred, however, were cap- 

 lured daily in the following manner, for the sake of sanitary researcb. Traps 

 were sel overnighl in scallered liouses, lliose containing rats ne\l moiuing 

 were removed to Ihe collecling station, each Irap being labelled wilh ihc 

 " address " of Ihe liouse from which it had been taken. One UKirning. live 

 melanic rats of the species Gunoini/s. bein/alcnsis were brought in from a certain 

 bouse. On the following nigbts, traps were agaiii set in Ihe same bouse and 

 in the neighbourliood. Finally. in ail. len individuals of tlie same peculiar kind 

 were caplured in two adjoining bouses, and no othei's ofany ollier kind enlered 

 lli(» traps set in those bouses during the lime. The members oflhis group could 

 be distinguished at a glanée from Ihe common brown liiaioini/!! even al a dis- 



