OF THE NUBIAN GIRAFFE. 225 
It is surrounded by two strong layers of muscular fibres. The external muscular layer 
is the thickest, and its fibres are nearly transverse in their arrangement: those of the 
internal layer are oblique, but approach towards the longitudinal disposition. I sub- 
jected them to microscopical observation, and compared them with the muscular fibres 
of the four cavities of the stomach ; they presented a structure which may be regarded 
as intermediate between that which characterizes the voluntary and involuntary muscular 
fibre. In the voluntary muscles the ultimate filaments are collected into what may be 
called ultimate fascicles, which present a uniform or definite size, and these are charac- 
terized, as is well known, by transverse strig: in the involuntary muscles, as those of 
the stomach of the Giraffe, the ultimate filaments are not collected into fascicles, but are 
uniformly interwoven with each other in a wavy course, and there are consequently no 
striated fascicles. In the muscles of the esophagus the ultimate filaments are aggregated 
into regular-sized ultimate fascicles, in which they present a parallel disposition: but 
the fascicles exhibit no trace of the transverse strie which characterize the voluntary 
fascicles, but, on the contrary, are perfectly smooth and sub-transparent. 
True involuntary fibres arranged round mucous membranes, as those of the intes- 
tine, or urinary bladder, may be thickened by increased action, but do not acquire a 
deeper red colour: the muscular fibres of the heart, which are developed in the vascu- 
lar layer of the germinal membrane, and which present the striated character, are 
generally the reddest in the body, and present the red colour in those animals in which 
all the other muscular fibres are white. Now the muscles of the @sophagus, which re- 
semble in their ultimate aggregation the true voluntary fibres, also assume a deeper red 
tint in the Giraffe and other Ruminants, in relation to the increased number and force 
of the contractions which they have daily to perform, as compared with the cesopha- 
geal fibres in the non-ruminating animals. 
The mucous membrane of the esophagus is thick and firm; it is lined by a well- 
developed smooth and polished epithelium, and is connected to the muscular coat by 
a very lax cellular membrane. 
Abdominal viscera. 
Before adverting to the rest of the alimentary canal, I may describe the position in 
which the abdominal viscera were seen in two dissections of the Giraffe. 
In the female, which died at the Surrey Gardens, the paunch occupied the ventral 
aspect of the anterior two-thirds of the short abdominal cavity, resting immediately 
upon the abdominal muscles and their strong and elastic fascie. The great omentum, 
which was studded with fat, as in the Deer and Ruminants generally, extended from 
the paunch to below the brim of the pelvis: on raising it, a fold of the colon appeared 
immediately below the paunch, towards the left side ; below this were several convolu- 
tions of small intestines: the obtuse blind end of the cecum made its appearance in the 
left hypogastric region, and below these was another portion of the colon. 
