CHAPTER II. 



THE GROWTH OF THE HOOF. 



MoLLER distinguishes three periods in the development of the 

 hoof: — (1) The period of general epidermal formation ; (2) The 

 period of the provisional hoof ; and (3) The period of the hoof 

 proper. 



The period of general epidermal formation comprises 

 the first two months of uterine life, during which one can 

 only distinguish at the extremity of the limb a slight 

 thickening of the epidermis, marking the position of the future 

 hoof. 



The second period extends over the third, fourth, fifth, and 

 sixth months of foetal life, during which are formed the 

 coronary band and the remainder of the keratogenous or horn- 

 secretincr membrane. At the seventh month the wall itself 

 appears distinctly, then the sole and frog, whicli are completely 

 developed soon after birth. 



The third period is characterised by the greater hardness of 

 the horn. Development takes place from the region of the toe 

 towards that of the heels. During the latter half of gestation 

 the hoof begins to assume the appearance of ordinary horn, the 

 chans^e conimenciii£^ at the coronet. 



At birth the hoof is conical in shape ; its horn soft and 

 elastic. The frog is greatly developed -and the sole is not yet 

 apparent. It is only towards the fifteenth to eighteenth month 

 that the hoof assumes its final form. At first like a truncated 

 cone with its base above, it gradually assumes a cylindrical 

 form, finally changing once more to the conical shape, but 

 with the base below. Tlie heels, formerly very oblique, 

 become parallel to the toe, and the sole develops a marked 

 concavity. 



An examination of the feet of a fuUv srown but unshod 



101 



