iyi9. Carpenter. — The Importance of Rats and Mice, 49 

 THE IMPORTANCE OF RATS AND MICE. 



BY PROF. GEORGE H. CARPENTER, D.SC. 



A PAMPHLET^ of modest size recently issued by the Trustees 

 of the British Museum, in which Mr. M. A. C. Hint on deals 

 with the importance of Rats and Mice in relation to human 

 health and industry, is worthy of study by all naturalists 

 who appreciate the value of zoological research from the 

 economic standpoint. As Dr. S. F. Harmer remarks in his 

 preface, " it is not sufficiently recognised by the majority 

 of the community how great " is " the extent of the damage 

 done to essential food supplies by these small mammals," 

 which are also " enemies of mankind " because of " their 

 agency in the dispersal of some of the most serious diseases 

 which affect the human race." 



The largest section of this valuable little book is occupied 

 with a description of the two common species of Rat — the 

 " Black " and the " Brown " — found in association with 

 mankind. Mr. Hinton favours generic subdivision so as to 

 call these respectively Rattus rattus and Rattus novvegiciis ; 

 the House Mouse is the only Britannic species for which 

 he retains the familiar Mus. A point of general biological 

 interest comes out in the account of the sub-species of 

 R. rattus ; the technical " type-form," with its black fur, 

 " is essentially characteristic of the cold northern countries 

 of Europe," and is in reality a modification of " a bright- 

 coloured soft furred stock," represented by the many local 

 sub-species which abound in India and Burma — countries 

 whence R. rattus has spread widely over the globe through 

 the exchanges of commerce. Irish naturalists will be 

 interested to see that Mr. Hinton regards the black variety 

 of the Brown Rat — the famous Mus hihernicus of William 

 Thompson — as a parallel case of colour-modification appa- 

 rently under climatic influence. " This black race," he 

 writes, " is becoming commoner and is acquiring a wide 

 distribution." 



'" Rats and Mice as Enemies of Mankind." By M. A. C. Hinton. 

 British Museum (Natural History) Economic Series, No. 8. Pp. 64, with 

 2 plates and 6 text-figures. London, 19 18. Price 15. 



