296 



BREEDING 



Table II. — Showing the Rate of Growth of a H-hands Horse during the 



First Year 



iyfjr/ r5 » « 12 I6 20 Zt- Z3 3Z 36 10 14- 48 S Z WEEKS 



' ' ^ ^ "" ■ /«o cm. 



(S3 In) 



130 cm. 



(36 -^n) 



(ZSIn) 



(18 in) 



^1 



•jncf 



Took to '-^rouni 



! round 



izo cm 



no cm. 



100 cm. 



80 cm 



(ssfi In) 



80 cm. 



10 c. m. 



eo c.m. 

 (zzn in) 



50 cm. 

 ts cm 



After the third year increase in height, if there is any, results almost 

 entirely from a further lengthening of the vertebral spines that form the 

 skeleton of the withers — the length of these spines is intimately related to 

 the size and weight of the head. In the male wapiti, e.g., the spines are 

 long; in the female, owing to the absence of horns, the head is lighter and 

 withers are aljsent. 



Of the increase of height durino- the first six months 17 "7 cm. are due 

 to the growth of the fore-limb from the point of the elbow downwards, but 

 during the second six months the increase of the foi-e-arm, wrist, and foot 

 is only 3 "7 cm., and after the first year the fore-limb from the elbow down- 

 wards only increases 1"4 cm. It is worthy of note that almost the entire 

 increase in the length of the fore-limb below the elbow is due to the 

 growth of the radius (fig. 565). The circumference below the knee in- 

 creases considerably during the first three months, but alters little during 

 the rest of the first year. In the case of the hind-limb there is a gradual 

 increase from the point of the hock during the first nine months, when the 

 maximum length is often reached — the increase is mainly clue to a lengthen- 

 ing of the phalanges and the heel process of the os calcis, not to the middle 

 metatarsal. 



