MISCELLANEOUS NOTES. 345 



its surface. It advances in a continuous succession of short leaps, the 

 length and frequency of which vary in accordance with the pace at which 

 it moves. The average length of each leap is about twelve inches, and the 

 whole movement is one of sinuous regularity though occasionally a walking 

 gait is assumed. The pliant body is at each leap flexed and the back is 

 arched ; the head is raised from off the ground, the eyes are widely opened 

 the body is propelled forward by a forcible contraction of the hind 

 limbs and gently alights on all fours at the termination of each bound. 

 The claws are elevated by an extension of the toes and this permits the 

 animal to rest on the soft pads of the feet and prevents the claws from 

 penetrating the soil and impeding its further progress. During slow motion 

 the tail is often elevated and curled over the back, thus displaying the 

 white subcaudal spot which makes the creature almost as conspicuous as the 

 white tail makes the rabbit when hastening to its burrow. But during any 

 rapid progression the long bushy tail is immediately lowered, prolonged out 

 behind, rigidly fixed and but very slightly elevated above the surface of the 

 body. The beautiful manner in which the parachute is folded beneath the 

 body, when not in use, renders it almost invisible during this movement, 

 but when the leaps are long and rapid the free margin of the thin membrane 

 may be seen flapping gently at each spring and may, possibly, to a slight 

 extent impede its motion and would undoubtedly prevent a still more rapid 

 progress. And here we seem to see a limit reached in the modification of 

 an organism for existence under two diverse conditions, as it is evident that 

 a greater development of this wonderful parachute to attain a freer aerial 

 motion will hinder the terrestrial motion, and similarly by a lesser develop- 

 ment the movement on the ground will profit at the expense of movement 

 in the air. When the attention is aroused or the curiosity excited, all 

 motion is immediately checked ; the animal stands firm, motionless and in- 

 tent ; the body is often raised or even erected on the hind limbs in the en- 

 deavour to discover the cause of the excitement ; the expression is fixed and 

 attentive ; the head is often raised and may be turned from side to side 

 or directed intently towards the sound or object of its alarm ; the eyes are 

 widely opened ; the ears are elevated ; the skin over the nostrils is wrinkled 

 and the vibrissse are directed forwards and vibrate slowly as though, like 

 the wide-open eyes and elevated ears, these tactile hair were of good ser- 

 vice to the creature in discovering the cause of a distant excitement. It 

 is, however, improbable that the vibrissae perform any definite sensory 

 function under such conditions but, since they are most valuable as 

 tactile organs when directed towards objects with which they can come in 

 contact and the nature of which they are endeavouring to ascertain, it 

 seems likely that their movements may be reflexly called into action in the 

 determination of all causes of excitement, near or distant, even when, as 

 tactile organs, they could produce no effect. When the body is raised 

 erect the hind limbs are flexed and the animal sits upon its haunches ; the 

 fore limbs either hang downwards or are extended towards the exciting 

 agent, as though to grasp it. The parachute is folded and concealed. 

 The position of the tail is variable but it is interesting to observe that, on 

 certain occasions, when attention or curiosity is aroused, the tail, which was 

 either elevated or curled over the back, is permitted to sink gently back- 

 wards owing to a complete relaxation of the elevatory muscles. Thus the 

 definite mental concentration of curiosity is associated with a definite 

 muscular tension of all those parts which tend in any way to the satisfac- 

 tion of that curiosity and, apparently, also in a definite relaxation of those 

 parts which are not so connected, for what value the tail could be for such 

 a purpose no one can say. But the external manifestation of internal 

 in so gentle and passionless a creature. The 



