g8 Records of the Indian Museum. [Voi^. ITT, 



rattus, but never a sport. However, this assertion may at any mo- 

 ment be proved to be erroneous. 



This idea of the relations of the many races of Oriental rats 

 to one another has not the merit of simplicity, and is not in ac- 

 cordance with the Linnean system of nomenclature. 



In concluding this appendix, I must acknowledge that as re- 

 gards many of the ideas expressed in it I am much indebted to a 

 book by R. K. Lock, entitled " Variation, Heredity and Evolu- 

 tion " (1907), which contains a clear exposition of the teachings 

 of Mendel, Bateson and De Vries, teachings which seem more 

 in accordance with nature than those usually expounded as 

 Darwinism. 



Lest it may seem that I have been unduly biassed by Mr. 

 Lock's book I hasten to add that "Mutation, Mendelism and 

 Natural Selection," by Professor E. B. Poulton (1908), has also been 

 read. The author of this essay considers that a natural consequence 

 of such ideas as those expressed in Lock's book is " a widespread 

 belief among the ill-informed that the teaching of the founders of 

 modern biology are abandoned." 



These opinions, therefore, are put forward with diffidence, and 

 I have felt the need of that criticism and discussion which are so 

 necessary to temper fresh ideas. 



APPENDIX III. 

 Enmity between the Various Races of Rats, 



The question of the cause of the ascendancy of particular races 

 is important. It has been assumed that the absence of Mus 

 decumanus from Madras is due to the fact that in its habits this rat 

 resembles Bandicota indica, and that since the bandicoot is much 

 the more powerful rat, it can secure the drains of the city for itself 

 alone. This raises the question as to whether special enmity be- 

 tween particular races exists. Some evidence has been obtained 

 and more might be the outcome of simple experiment. 



The subject was first brought to m}^ notice by Captain Davys, 

 who found that if a living shrew were placed in a cage with a young 

 living Mus rattus, the shrew seized the head of the rat with its 

 powerful incisor teeth and after biting through the skull devoured 

 the brains. I was subsequently reminded of this habit of the shrew 

 when at Rangoon. It happened that a cage containing a living 

 shrew (the grey " musk rat " Crocidura ccerulea) was placed in con- 

 tact with a pile of dead Mus concolor. The shrew dragged the foot 

 of one of the rats through the bars of the cage and commenced 

 devouring it. The dead body of the rat was placed inside the cage. 

 The shrew continued to devour it, applying itself to the extremities, 

 the snout, muzzle, ears and feet in succession. Six living Mus 

 concolor were placed in a cage with one shrew ; without a moment's 

 delay they combined forces against the shrew. The fact that they 



