DIGESTIVE TRACT OF THE CAT. 



33 



position of the other viscera. It is attached to the dia- 

 phragm, and is also connected to the stomach by means of 

 the lesser omentum. Its tissue is soft, the adjoining organs 

 press against it, so as to produce permanent impressions upon 

 it, and perhaps even to affect the growth of single lobes, but 

 they are incapable of moving it bodily in any direction. On 

 the examination of a number of livers which have been 

 hardened in situ, one cannot fail to be impressed by the great 

 extent of their normal variation. Not only do they diifer in 

 shape when considered as a whole, but there is also an enor- 

 mous variation in the individual lobes, and some of them 

 seem to be more prone to it than others. 



It is difficult to explain why there should be so much 

 more variation in the size and shape of this organ in the cat 

 than in the human species, but such is certainly the case, 

 and these variations are not confined to the adult animal, 

 but are found in the embryo as well. 



The liver grows with great rapidity, and it is natural to 

 suppose that its increase in size would take place in the 

 direction of least resistance, which I believe to be the case. 



The individual variation in the external form of an 

 embryo might tend to favor the development of one lobe to 

 the detriment of another, and, as has been stated above, it is 

 not very rare to find a portion of the liver within the cavity 

 of the umbilical cord. It would seem quite possible that this 

 might occur either if the point of communication between 

 the coelom and the cavity of the cord was actually more ca- 

 pacious than usual, or if its contents were not quite as fully 

 developed in one case as in another. 



Furthermore, one lobe has the power to supplement a 

 deficiency of growth which may exist in an adjoining lobe, 

 and this is especially true of the embryo. For example, on 

 opening the abdominal cavity of an embryo one would expect 

 to differentiate a right lateral from a caudate lobe, but often 

 there is no fissure visible. On a closer examination the cau- 

 date lobe will be found to be undeveloped, and to lie entirely 

 concealed beneath the duodenum, whereas the lateral lobe 



