REVIEW. 
78 
a very clear day, these villo-papillse appeared of a conoid 
form, having their broad parts or bases attached to the reti- 
cular tissue, while their middles became contracted, and grew 
pointed, the extreme points shewing, in many instances, sorts 
of olive-shaped buttons, altogether resembling so many little 
drum-sticks. 
Around the villo-papillse is observed a delicate membrane, of 
a greyish white colour, sometimes exhibiting black patches, 
continuous with the superficial layer of reticular tissue. This 
membrane, which envelopes the vascular nervous villo-papillary 
tissue underneath it, constitutes what I call the keralogene or 
blenogene of the villo-papillse, because it secretes the epithe- 
liums constituting the horny tissue. 
The tissue contained within this membrane is formed essen- 
tially of vessels and nerves. The arteries, two in number, rarely 
three, are prolonged to the bottom of the sheaths in order to 
meet the veins, and thus form one or two remarkable arches. 
The veins, much larger and more numerous than the arteries, 
anastomose very freely with one another, forming inflexions and 
arcs before uniting into two or three single trunks which run to 
empty themselves into the larger veins, at the base of the villo- 
papillse, and afterwards join those, more numerous, of the reti- 
cular tissue. The vascular apparatus first described is not 
visible but through the microscope, magnifying from 150 to 
250 times, and altogether amount to no more than a capillary 
network. 
I have been able to descry some fine nervous threads upon 
the base of the keratogene organs, but I have never been able 
to trace them any farther. Nevertheless, I hope to trace them 
even to the very extremities of the sheaths, since they must, of 
necessity, exist there. 
Such is the organization of the villo-papillse of the sole of the 
foot, and of the inferior border of the laminated tissue, parts 
which, we have seen, are most delicately constructed. Lastly, I 
may remark, that it is these villo-papillse which are concerned 
in the secretion of the horn. 
If, after long maceration, the hoof is detached from the sub- 
jacent tissues, and a transverse section is made of it between 
the crust and the sole, about from 2^ to 4 inches from their re- 
union, there come very visibly into view upon the inside of the 
hoof, as well as the bottom of the laminse, and upon the entire 
surface of the sole, multitudes of small holes, perfectly isolated 
one from another, placed at nearly equal distances, very like, 
altogether, the perforations of a fine sieve. These little holes, 
which are named the pores or porosities of the hoof, are the 
superior receptacles of so much of the canals or tubes of the 
