388 JOURNAL, BOMBAY NATUBAL HIST. SOCIETY Vol. XXII. 



Mus alexandrinus. He mentions a case at Poona where a small colony 

 of these rats was discovered. They were confined to nine houses, and 

 apparently no other white-bellied i-ats were found in Poona amongst the 

 45,000 caught between 26th May 1908 and 22nd May 1909. In Capt. 

 Lloyd's opinion there are only two possibilities to account for these rats, 

 the one that they were mutants and the other that they had migrated 

 in from outside. ' 



On page 74 a table is reproduced, giving the number of whole coloured 

 and white-bellied rats caught in different towns throughout India to show 

 how rare {?) this variety is supposed to be. 



It is interesting to compare some of these figures with the Mammal 

 Survey Results and as the town of Belgaum is no great distance from the 

 Dharwar and Kanara Districts, it may well be compared with them. 



"Whole coloured White- 

 rats, bellied. 

 Belgaum. , . . . . 39,^60 . . Plague Commission. 

 • Dharwar and Kanara 



]5istricts .... 52 43 Mammal Survey Col- 



lector. 



It might also be added that out of 84 rats caught by the Survey Collector 

 in the Central Provinces 39 were of the white-bellied variety. 



Of course to a certain extent the survey specimens may be selected, but 

 even then it shows that the white-bellied variety is commoner than Capt. 

 Lloyd supposes. Perhaps the whole-coloured M. rattus may be more of a 

 domestic animal than its white-bellied cousin. ' 



The origin of species from mutants is discussed, and Capt. Lloyd is of 

 the opinion that s]3ecies have arisen in that way without the help of 

 natural selection. 



Towers, work on the potato beetles in America is quoted and compared 

 with the Author's work on rats and a coloured plate is reproduced from 

 that iDaper showing the different sports and mutants found amongst these 

 beetles. In Chapter X the avithor points out the bearing of the mutation 

 theory in practical matters and its connection with certain branches of 

 pathology, especially in regard to diseases. 



We can recommend this book to any one interested in evolution : it is 

 well printed and nicely got up, but it is unfortunate that there is no index 

 or table of contents, so that it is almost impossible to find anything without 

 going through the whole book. 



