350 JOURNAL, BOMBAY NATURAL HIST. SOCIETY, Vol. XXllI. 



is rigidly trailed behind. Downwards and onwards it swoops in a beautiful 

 gliding motion, ever increasing in speed as it draws nearer and nearer to the 

 lower limits of its "flight," when suddenly it seems to swerve; its momen- 

 tum raises it a few feet upwards ; its pace checks and its curved claws 

 strike inwards and cling into the tree as it reaches its goal in safety. The 

 tail has been considered to act as a kind of rudder by which the animal 

 can guide its movements and actually change direction when in the air. I 

 have never seen the gliding motion take place in any direction but that of a 

 straight line except in the sudden elevation at the termination of the 

 "flight," Moreover it is extremely improbable that Nature would have 

 provided the animal with a steering gear in the form of an elongated and 

 cylindrical bushy tail ; it appears more probable that it acts as an organ of 

 balance, for of what value coiild the similar long bushy tail be to steer the 

 Common Squirrel which never flies. Just as the tail of a bird cannot act as 

 a rudder because it is compressed in the wrong direction, so also it is 

 unlikely that the tail of the Flying Squirrel will possess a steering function 

 as it is not compressed at all. It has been shown that when the animal 

 is seated on a branch an excess of weight in the anterior portion of the body 

 is counterbalanced by an elevation of the tail which increases the leverage 

 power of the posterior part of the body, and when the Squirrel is gliding 

 through the air the obliquity of its position produces a considerable depres- 

 sion of the anterior body which would tend to upset the equilibrium and 

 cause the animal to topple over were it not that the tail prolonged out 

 rigidly behind was sufficient to counteract the forward depression and 

 result in the maintenance of an even balance. 



As closely as I could estimate, the square surface of a rather small 

 specimen, with parachute folded, was 33i| square inch and, with parachute 

 widely extended, reached 116 square inch and this gives to the animal, when 

 in the air, an increase in square area of three to four times over that which it 

 occupies when at rest. 



The distance over which the gliding motion will carry the animal is very 

 considerable and Jerdon records a flight which extended to sixty yards. 

 The Common Squirrel, though possessing not the vestige of a parachute, 

 will, when performing leaps of any considerable extent, stretch out its limbs 

 and extend its long bushy tail. This position may possibly support the 

 animal to a slight extent and may be considered as the first step in the 

 succession of evolutionary gradations towards the development of a distinct 

 sustaining membrane which ultimately increases to almost a fourfold degree 

 the supporting power of the animal. 



Nature controls with prudence all the varied parts of her beautiful 

 dominion. There is no squander, nothing superfluous yet every corner is 

 amply filled with living creatures marvellously adapted to their conditions 

 of life. Miles aloft in the blue sky, in the profound depths of the bound- 

 less ocean, everywhere swarming on the surface of the land can be seen 

 these wondrous modifications with which Nature has provided all the living 

 inhabitants of her world. Few creatures play a more lovely part in this 

 economy of existence than the little Flying Squirrels of our empire. 



No. v.— ALTITUDE TO WHICH ELEPHANTS ASCEND. 



In the Illustrated London Neivs of April 18th there is a diagram showing 

 the vertical distribution of animal life. 



Amongst the animals shown, the Indian Elephant is placed at 5,000 ft. 

 During the recent Aka expedition, we found Elephants on the Butan- 

 Tibet boundary at a height of 10,200 ft. It would be interesting to know 

 if they have ever been observed formerly at this height. The elephants 



