MAMMALS 25 



Tupaia ferruginea | Unicolorous above, rufous-yellow below. 

 Sciurus notatus j Low country. 



Sciurus jentinki j and thin. Low country. 



His } 



j- A similar pair to the above. Low country. 



Tupaia gracilis 

 Sciurus tenuis 



Tupaia montana ] Unicolorous, rufous-brown above, paler below. 

 Sciurus everetti J Mountains. 



Funambulus laticaudatus is very similar in colour though a little 

 paler ventrally ; the snout is markedly elongate, and so some- 

 what resembles that of a Tupaia. 



Tupaia tana 1 Striped dorsally. 



Funambulus insignts diversus ) 



Tupaia picta and T. dorsalis also have dorsal stripes, but in none 

 of the Tree- Shrews is the striping so well marked as in the 

 squirrel. 



The local correspondence in these resemblances is 

 especially noteworthy. Thus, on Mt. Penrisen Sciurus 

 everetti replaces the common low-country species S. 

 notatus, and the very similar Tupaia montana is found 

 there instead of T. ferruginea of the lowlands. 



This segregation in given localities of similarly coloured 

 species, belonging to two very different orders of mam- 

 mals, is evidence enough that the resemblances are not 

 fortuitous, but it is by no means easy to explain them 

 satisfactorily. It has been suggested that these facts 

 must be classed under the heading, Aggressive Mimicry, 

 it being supposed that the insectivorous Tree-Shrews, by 

 their mimicry of the harmless vegetarian Squirrels, are 

 enabled to approach more easily their unsuspecting prey. 

 There are a great many difficulties in the way of accept- 

 ing this view. In the first place it is by no means 

 certain that the species of Tupaia feed very largely on 



