n. E. LI.OYf». — VAIIUTION \\\n\\\ ïllR n \TS (H- i\|il\. 



VARIATION AMONG THE RATS OF INDIA 

 By R. E. LLOYD 



lll.ll.in diiMl SiTVIi-.v Pi-,,l,.^^ui-nriil,il,,;;y lu Ml,. MrJi.Ml l\u\\i"AO ni lli'n^.-ll. 



The following is a short account of an investif>-alioii wliii-li lias heen car- 

 ried on in India, diirinj,'- Ihe last l'ew years. 'l"he primarv purpose nC lliis invos- 

 ligalion was lo obtain général Knowledge, concerning tlie house rais of Ihe 

 towns and villages, such as mighl lead lo some nieans of checking tlie ravages 

 ni" Plagnc. Sanilary matlers do nol concern us direclly, bnl in Ihe eonrse of 

 Ihe inquiry sonie interesling facts were ohserved whicli may well he deserihed 

 hère; since, in Ihe lerminology of (ienelics, Lhey alîord examples of the sndden 

 appearance of new characlers among animais in Nature. Moreover, sueh new 

 characters were seen not only in single individnals isolaled among Ihe normal 

 mullilude, bul also in small groups of individuals whiih proliably ar(is(> froni 

 single individuals hy in-breeding. 



Since Ihe year l'.lllà, Ihe destruction of rats lias heen carried ont on a large 

 scale in many parts of India. In some towns, Ihis bas been doue in a svslemalic 

 manner, for the sake of sanilary research, by Ihe officiais of Ihe IMague Com- 

 mission; under their guidance, information concerning eaeh rat caplured was 

 recorded wilh an appended number in a register. For example, '(."> iST rats 

 were Ireated in this manner during one year al Poona. In olher places, Ihe 

 destructive measures were carried out solely wilh Ihe inlenlion of slamping ont 

 the disease hence indiyidual records were not kepl. \\'illi Ihis ])ur)iose. bel ween 

 three and four Ihousand rats were destroyed daily in Rangoon, llirouglidul Ihe 

 year l'.KIS. 



.\s a temporary workei' in the Indian Muséum at Calcutta, I look a minor 

 part in Ihis work. At Ihis Inslitution I received spécimens, in the forni of 

 dried skins and in alcohol, and collected information from many parts of India 

 and Burmah. Also, I visited some of Ihe larger towns where rai desirnclion 

 wns in progi-ess. 



'/'/((■ noriiiid spor'ifs. 



Before describing the abnormal kinds or sports it is necessarv lo ineiilion 

 very brielly. two species f)f rats which are common in Indian lowns. Bv far 

 Ihe commoncsl is il/«s railii^. a species of world wide distribution. Spécimens 

 of Ihis species. sent from England, were compared with Indian spécimens and 

 with olhers from a port in Ausiralia. The bodily proportions and the form of 

 Ihe skull were very alike in ail. In the skins from England, the fur was ralber 

 longer and denser Ihan in Ihe dlhers. The gênerai appearance of the species is 

 well known. The mean length of the head and body combined, as measured 

 from the lip of Ihe nose lo the anus, is aboul 17 cms. : the lail is longer Ihan 

 Ihis. being nlHiiit l'Il cms. The cars are large and projecting, when laid forward. 

 lhey usually cdvci- Ihe wliole of the eyes, which are large and very promineni 



during life. The an lenglli of Ihe liind fnot is slightly over ."i cms. The fonii 



aiid arraiigeinenl of llic pads on Ihe soles of Ihe l'cct arc verv characleiislii' sd 



