REVIEW—RIGOT’S ARTICULATIONS OF THE HORSE. 493 
1. That the synovial fossae, which by some have been mis¬ 
taken for ulcerations causing lameness, are frequently to be found 
in the articulations of all our domestic animals; but more par¬ 
ticularly in the solipedes. 
2. That they are developed as the animal advances in life, and 
as his labour is great. 
3. That their appearance is quite different from that presented 
by cartilage when suffering under the effects of inflammation ; 
for instance, the inferior surface of the diseased navicular and 
those of the cuneiform bones of the hock affected with osseous 
spavin. 
4. That, when found in a diseased condition, it is always in 
conjunction with an altered state of the synovial membrane. 
From these facts we are induced to believe, in common with 
professors Dick and Rigot, that, so far from these fossae being 
the result of disease, and one of the causes of hock lameness, they 
are neither more nor less than reservoirs for supplying with a 
lubricating fluid those parts of the articulation which, by their 
mechanical relations to each other, are most liable to be affected 
by friction. 
Frequent examinations of diseased articulations in the horse 
settled the dispute so long on the tapis between human patholo¬ 
gists, as to whether or not the diarthrodial cartilages are pos¬ 
sessed of a sufficiently high degree of organization to be acted 
upon by their own vessels. 
How often is ulceration seen to commence on the free surface 
of cartilage, when there is not even the slightest trace of any 
process or elongation of the synovial membrane having commu¬ 
nication with the ulcerating surface, as described by Mr. Key, 
in the “ Medico Chirurgical Transactions.’’ This gentleman 
seems to think, that absorption of the cartilage cannot, with 
propriety, be attributed to any change originating in the cartilage 
itself; but to the vessels of the synovial membrane. It is a 
curious theory, of one part of the body being absorbed by the 
mere contact of another, especially when there is no continuity of 
substance between them. We must confess that we are doubtful 
as to its possibility, there being no means of proving the veracity 
of such a statement. This, however, is not going so far as Cru- 
veiller, who says, that the diarthrodial cartilages are totally devoid 
of vitality. We have only to examine the changes they undergo 
in herbivorous animals, to be thoroughly convinced of the fallacy 
of such an assertion. We have succeeded more than once in 
tracing vessels running from the articular edge, under the cartilage, 
to its centre, where they passed through its thickness, and were 
eventually lost on the surface of a very supcificial ulceration. 
