CONTRIBUTIONS TO ZOOLOGICAL PATHOLOGY. 
137 
tion was found to be thick, and very firm, especially towards its 
anterior and superior part, and seemed to be implanted on the ilium, 
a little further forward than usual : the superior extremity of the 
shaft of the bone was turned inwards, and was lost in the sub- 
stance of the ligament, so that the prominence of the trochanter 
major was destroyed. On removing this ligament, the entire cervix 
and articular head of the bone was found wanting, and their place 
was occupied by a flat elongated eminence : this was situated be- 
tween the rudimentary trochanters, and placed almost on the an- 
terior aspect of the bone : it was rather rough upon its surface, a 
small portion of which only was covered by cartilage, particularly 
at its superior part. The edges of it were thick and rough, and 
gave attachment to the capsular ligament. The cotyloid cavity was 
found in a correspondingly rudimentary state ; the brim was so 
much flattened as to destroy entirely the appearance of a cavity, 
the natural position of which latter was indicated by the presence 
of a quantity of fat. The superior part of the brim alone was 
covered by articular cartilage, and beyond this there was a thin 
membranous ligament corresponding to the cotyloid, which, at the 
rudimentary notch in the inferior part, stretched across as a firm 
band, the transverse ligament, but without giving off any fibres to 
the head of (he bone to constitute the inter- articular ligament. No 
articular cartilage existed in the rudimentar}' cotyloid cavity, the 
entire fossa being filled by the Haversian gland ; and the only 
point upon which the head of the thigh-bone had moved was upon 
the superior edge of the cotyloid brim. The left side was perfectly 
normal in structure. A reference to the accompanying plate will 
explain all the relative appearances which we have described 
above. 
On looking to the mechanism of this rudimentary articulation, 
therefore, it might be supposed that considerable lameness had 
existed; but on inquiring at the keeper of the animal, I found 
that, though she was “rather ricketty in her movements,” as he ex- 
pressed it, yet she was able to walk and leap with comparative 
freedom : still, from the freedom of play that existed between the 
articular surfaces, the different movements could not have been 
performed with much steadiness. As a comparative pathological 
specimen of this rare form of malformation, it is almost unique in 
itself, whilst the appearances which it presents contribute much to 
the explanation and elucidation of the same condition of parts in 
the human individual. In man the same class of cases would 
scarcely present the same extent of arrestment in the development; 
but this depends on a very obvious cause. In the lower animals 
their state of independent existence must be much more early 
assumed than in him ; and as greater physical exertion must be 
VOL. XVII. T 
