THE RING-TAILED LEMUR 13 



tactile function. These glands occur in certain other 

 lemurs ; Garnett's galago has one situated on the 

 ankle instead of the forearm, consisting of a tuft of 

 spiny outgrowths. The function of these curious 

 structures is as yet unknown, though it has been 

 suggested that they may act as climbing irons, 

 just as the scales under the tail of the African 

 flying squirrels assist them to swarm up tree-trunks. 

 It has been stated that the range of the ring- tailed 

 lemur is limited to the central table land of Mada- 

 gascar, on the south and south-western borders of 

 the Betsileo province; the Leyden Museum, however, 

 contains a male specimen which Pollen and Van 

 Dam's expedition obtained in 1865 at St. Augustine's 

 Bay, on the west coast of the island. The province 

 of Betsileo is remarkable for its magnificent scenery 

 of bold mountain ranges ; there are also many 

 isolated peaks, lofty and precipitous, which serve as 

 landmarks. Several fine rivers flow from east to 

 west to empty into the Mozambique Channel ; 

 although some of them are encumbered by rapicls, 

 others are broad magnificent waterways. Many of 

 the valleys are adorned with the famous ravinala 

 (traveller's tree) or tangled with bamboo thickets; and 

 so dense is the undergrowth in these places that two 

 travellers cannot march abreast. Some of the hill- 

 sides are volcanic, littered with lumps of dark brown 

 rock (slag or scoria ?) and full of bubble-holes : hard 

 ridges of stratified sandstone occur here and there, and 



