A SHORT NOTE 



ON THE 



Indian Rats probably concerned in the propaga= 



tion of Plague, with instructions as to 



the preservation and measure= 



ment of specimens. 



The fact that rats play an all-important part in the propaga- 

 tion and maintenance of endemic plague has resulted in the issue 

 of instructions from the Government of India for the preparation 

 of a pamphlet for the guidance of Medical Officers and others 

 engaged on plague work. The goal at which the pamphlet aims 

 is that our knowledge of the rats chiefly concerned with plague, 

 their habits and distribution, at present sadly deficient, shall be 

 so extended and amplified that we may be able to collect a 

 sufficiently comprehensive and accurate mass of facts to justify 

 final and definite conclusions. It is proposed to attempt to 

 achieve this aim by presenting a short and clear account which 

 will make it comparatively easy for any one at all interested in 

 the subject to identify the common rats occurring in his district, 

 and in the second place by the preparation of a series of instruc- 

 tions as to the preservation and labelling of specimens. 



As the result it is hoped that the authorities of the Indian 

 Museum will soon find themselves in the possession of such an 

 amount of well preserved and accurately described material as 

 to enable them to attack the problems at present awaiting 

 solution, problems that only a widespread and systematic collec- 

 tion of specimens can settle. 



The great difficulty in dealing with rats from the zoological 

 point of view is that in external appearance there is extremely 

 little difference, so that, to one who is not an expert, specimens 

 belonging to entirely different genera may present an apparently 

 identical appearance. As a matter of fact, if sufficient attention 

 is paid to minute details of measurement, such as the relative 

 proportion borne by the hind feet to the total length of the head 

 and body, there is little difficulty in separating genera, but with 

 regard to species, particularly of the genus Mus, the points of 

 difference relied upon are so minute and ill-defined that the sub- 

 ject is at present in a state of great confusion. Such differences 

 as depend on minute variation in the configuration of the cranium 

 and in the conformation of the teeth can only be dealt with by 

 some one with technical knowledge and considerable practical 



