REVIEW—RIGOT’S ARTICULATIONS OF THE HORSE. 451 
distinct one from the other, having no communication between 
them. 
In speaking of the articular cavity between the femur and patella, 
M. Rigot says that the synovial membrane is very extensive, and 
is not disposed in the same manner in all subjects, and that in 
some instances there is a free communication between this cavity 
and one, or sometimes even both, of those belonging to the fe- 
mero-tibial articulation. These communications, when they exist, 
are to be found at the junction of the anterior with the posterior 
condyles of the femur. In some subjects there is at this place 
a small furrow, to which certain reflections of membrane are 
firmly attached, thus closing all communication. 
M. Rigot asserts, that often-repeated examinations of this ar¬ 
ticulation have convinced him that this communication does not 
in any instance exist in young animals. Here we must differ 
from him, and widely; for although his observation holds good as 
a general rule, it is by no means without numerous exceptions. 
We have repeatedly seen these foramina both in young foals and 
in foetuses. 
Where it occurs in such very young subjects, the communica¬ 
tion is not the result of a perforation in the mediastinal mem¬ 
branes, but of a small space between their border and the condy¬ 
loid isthmi of the femur. In nine-tenths of the aged horses 
examined, there will be found these foramina communicating be¬ 
tween the cavities of almost every joint of the body, but more 
particularly in the stifle. 
To M. Rigot is due the honour of having first publicly noticed 
this anatomical fact in the adult animal. It satisfactorily ex¬ 
plains why some cases of opened stifle-joint are much more 
complicated than others. 
We extract the following from the chapter containing a de¬ 
scription of the articulations in general. The passage, though 
short, is valuable, inasmuch as it alludes to a subject which 
was lately the cause of a warm altercation between two highly 
talented veterinarians :— 
The synovial cavities appropriated to the same use as the 
articular margin (for the purpose of acting as reservoirs for 
synovia) and furnished in the same way with a synovial mem¬ 
brane, are sometimes placed on the side of the articulation, at 
others, on the articular surface. They are little sulci, of an irre- 
g^ular form, having their surfaces of a very pale pink colour. 
The inferior extremity of the humerus, and the anterior surface 
of the ulnar, present this sort of cavities. One ought to be well 
guarded against considering them as abnormal denudations.'* 
Here it is very evident that M. Rigot believes, with Professor 
