1909. | ANATOMY OF CERTAIN UNGULATA. 167 
the czeco-colic ligament extends down to the end of the cecum 
more or less along the inner of the two muscular bands only, this 
ligament is much less extensive in H. dorsalis. It lies, as in 
Hf. capensis, upon the outer of the two muscular bands of the 
cecum, 7. e. that on the colic side of the cecum, but does not 
extend back even so far as the point where the two bands unite to 
form a single muscular band. 
The cecum of H. dorsalis then, like that of H. capensis, shows 
on the ventral side two longitudinal teeniz where only one perhaps 
would have been expected. I take this to mean that the space 
included between these two muscular bands is the ventral surface 
of the median chamber of the cecum, which is so apparent 
dorsally between the two lateral chambers and is externally 
divided from them by two muscular bands bearing blood-vessels 
which are continuous in front with the ileo-colic mesentery. 
When the cecum is dilated with fluid, these bands are seen to 
produce much puckering of both the median and lateral portions 
of the cecum. When the cecum is cut open these three chambers 
are recognisable, but there are no permanent folds dividing them ; 
the walls of the cecum can be pressed flat. On the other hand, 
there are two anterior chambers of the cecum, right and left, 
which are divided from the rest of the cecum by permanent 
though low folds which cannot be stretched out flat; they are 
actually valve-like thickenings of the walls of the cecum. These 
lie in front of the entrance of the ileum and closely embrace the 
dilated commencement of the colon, the bands bearing blood- 
vessels already referred to upon the dorsal side of the posterior 
region of the czecum divide them off from the median “ chamber” 
of the posterior region of the cecum. 
I have recapitulated these facts, firstly to show the general 
resemblance of H. dorsalis to H. capensis in the form and sub- 
divisions of the cecum, and secondly to emphasise another 
difference between the two species. This is the extension back- 
wards of the median dorsal chamber beyond the two lateral 
chambers, so that it can be seen on the ventral aspect of the 
cecum in Hf. capensis. This is not the case with H. dorsalis. 
There are thus two quite distinct differences between the ceca of 
these two species. The two chambers already referred to which 
embrace the terminal section of the cecum or the beginning of 
the colon, according to the interpretation preferred, are spoken of 
by Lonsky * as the “ mittlere Etage” of the cecum, lying in fact 
between the lowest story which forms the blind end of the cecum 
and the upper story out of which emerges the colon. Jam inclined 
to consider that this region is potentially double—a meeting of 
the actual folds which delimit each half would convert each half 
into a tube—as indeed it appears to be externally. In this case 
a comparison may be fairly made with the two cecal appendages 
of the Manatee’. Lonsky has indeed compared the cecum of 
* Jen. Zeitschr. xxxvii. 1903, p. 580. 
+ Maurie, Trans. Z. S. viii. pl. 23, fig. 28; & Beddard, P. Z.S. 1897, p. 50, fig. 3. 
