A SHORT NOTE ON THE INDIAN RATS. 5 



convenient form of record is exemplified as follows : — f ; the upper 

 figure means 2 pairs of pectoral or breast teats while the lower 

 figure means 3 pairs of abdominal teats. An asymmetrical 

 distribution may be indicated as follows — § -j-f, the teats of the 

 right side being given first. A ticket with the register number, or 

 still better a ticket with number and full measurements, should 

 be attached to the rat before it is handed over to the skinner, 

 with a duplicate ticket for the skull. The method of labelling of 

 the skull has already been described ; the material of the skull 

 label is important as the skull has to be boiled. Tin foil which 

 is quite soft and can be easily perforated and scratched is best; 

 lead or a piece of ordinary biscuit tin will do. In the column for 

 remarks it should be stated whether the rat is found dying in 

 numbers in the plague season, i.e., whether it suffers from plague, 

 if positive information on the subject is available. 



The advantage of the register is that in case of a label becom- 

 ing partially destroyed or illegible a reference to the register is all 

 that is required. The advantage of the fully written up label is 

 that a huge amount of work is saved at headquarters. 



YOUNG RATS. 



Considerable difficulty may be caused to the beginner if he 

 does not know how to recognize a young rat, as its general 

 appearance i and i proportions may differ considerably from that of 

 the adult. The coat tends to be grey and furry, almost mole-like, 

 owing to the grey underfur showing up through the longer hairs ; 

 for the same reason the belly is much darker than in the adult. 

 The head is proportionately large, but the foot is a much more 

 certain and easily recognized guide. It may be relatively almost 

 twice as large as in the adult. The rule may be laid down that 

 if the hind foot is as much as 30 per cent of the length of the 

 head and body, the rat is a very young one, only just cutting its 

 third molar, and has only attained 50 or 60 per cent of its full 

 length. In the full grown adult the hind foot is only about 

 20 per centjof the body length, and in an exceptionally large and 

 old specimen may be as low as 16 per cent. In some of the 

 Nesokias the foot may be very large even in the adult (as much 

 as 25 per cent), so that the rule has to be somewhat modified, but 

 this is a point on which more information is required, particularly 

 as to the size of the foot in immature specimens. 



COLORATION. 



The coloration of rats is a character on which considerable 

 stress has been laid as a means of differentiation, much more indeed 

 than is justified. A large number of rats have very much the 

 same colour, and the minute differences that are sometimes 

 described are vitiated by the fact that the great range of colour 

 which may be present in different individuals of the same species 



