CHAPTER III 
GENERAL PHYSIOLOGICAL AND ANATOMICAL 
OBSERVATIONS 
Tue matter embraced by the heading of this chapter will 
offer for discussion many subjects of great interest to the 
veterinary surgeon. Around some of them debate has for 
many years waxed more than keen. Of the points in 
dispute, some of them may be regarded as satisfactorily 
settled, while others offer still further room for investi- 
gation. 
In this volume we can only hope to deal with them in 
brief, and must select such as appear to have the greatest 
bearing on the veterinarian’s everyday practice. 
Always prolific of heated discussion has been one question: 
‘Are the horny lamine secreted by the sensitive?’ To 
answer this satisfactorily, it will be best to give a short 
account of the mode of production of the hoof in general. 
A. DEVELOPMENT OF THE HOOF. 
Starting with the statement that it is epidermal in origin, 
we will first consider the structure of the skin, and follow 
that with a brief description of the structure and mode of 
growth of the human nail, a short study of which will 
greatly assist us when we come to investigate the manner 
of growth of the horse’s hoof. 
Tue Sxin is composed of two portions, the Epiprrmis 
and the Corrum. 
Tue Eprpermis is a stratified epithelium. The super- 
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