THE ACT OF LEAPING. 125 



possible for it to amount to no more than a jump or a bound off 

 and upon the same ground, as is the case when a horse is said to 

 " buck" in his leaping, i. e. to come down upon or near to the spot 

 from which he arose. 



Borelli commences his chapter " de saltu" with the proposition 

 that no leap is made without the joints of the feet being first 

 flexed*, and instances man as with straightened limbs being inca- 

 pable of leaping. Brutes and insects, however, from having their 

 joints already flexed, can leap at pleasuret. Horses with their 

 flexed fetlocks and angular haunches and shoulders, are ever ready 

 to spring off the grounnd, and the more lengthy and angular these 

 parts are, the greater the animal's power of jumpingj. We see 

 this well exemplified in the deer kind, and in rabbits and hares, 

 and especially in kangaroos, but most beautifully of all in many 

 of the insect tribe §. Horses take leaps with most facility and 

 effect when cantered or galloped at them at a moderate rate, be- 

 cause in that pace they are already prepared to jump, the leap 

 itself being, in fact, but an extraordinary effort of spring and 

 stride made after the manner of, or thrown into, the gallop. The 

 effort made by the extensor muscles to effect the bound into the 

 air is succeeded in the air by a contraction of the flexors : both 

 the fore and hind limbs are in the air drawn up towards the belly, 

 in order that the leap be effectually cleared. No sooner, however, 

 does the descent commence* than the fore limbs become spread 

 out forwards and the hind ones let down, wide apart, to receive 

 the body at the landing, and by their yielding position to ward off 

 or mitigate, as much as possible, the concussion consequent on 

 coming to the ground. 



LECOQ has happily represented the directing power of the head 

 and neck in the leap : — " The elevation of the neck governs the 

 direction of the leap. If the animal, in order to clear an obstacle, 



* Saltus non fit, nisi prius articuli pedum inflectantur. 



f Bruta et insecta aliqua, quae omnium pedum aut saltern postremorum 

 articulos semper inflexos retinent, possunt ad libitum saltare. 



I Quo longiores sunt vectes extremi crurum, saltus majores fiunt. 



§ HiDc est, quod locustae, grilli, et pulices longos ■ saltus efficiunt, quia 

 nempe eorum pedes posteriores valde prolixi sunt, ut sequent aut superent 

 longitudinem ejusdam animaleuli. Contra in hominibus et quadrupedibus. 



