THE LIVER 223 
ascertained to assist in this matter unless the position of 
abscesses and hepatitis relative to cholecystitis have a 
bearing; some discussion of this will appear later. We 
have not observed any peculiar pathology of the lobes of 
Spigelius and Riedel. In so far as the size and arrange- 
ment of the organ is concerned a few general facts of 
significance may be mentioned. 
It was formerly thought that the liver varied inversely 
as the size of the animal but Magnan (1) and others have 
shown that the matter is not so simple. In the first place 
if there be an actual mathematical formula it is that the 
liver varies in size inversely as the surface area of the 
body, but this is not the whole story. It seems that the 
relation of size of the organ to its weight is not constant 
and that it is better to judge of the organic capacity by 
the latter. In herbivorous animals, both birds and mam- 
mals, the liver is lightest per kilo of body weight ; next in 
weight are in order, fisheaters, meateaters, insectivora, 
seedeaters, fruiteaters and omnivora. There is besides 
this a roughly inverse ratio between the size of the liver 
and the length of the intestine and in the class Aves 
inversely as the size of the lungs also. From the im- 
mediately foregoing statements it is apparent that a 
bewildering variation occurs and that only rough 
measurements of the relative volume of the liver are avail- 
able. An attempt was made in the Marsupialia, which 
present all the variations given, to discover if any peculiar 
pathology corresponded with the above groups ; as it was 
fruitless, no change from our zoological treatment will 
be made. 
Lobar arrangement varies from the relatively simple 
double avian type to the manifold lobulations of the seal 
or the marsupial but I can find no literature to indicate 
that lobes or lobulations have a direct effect upon func- 
tions. There must be a difference of blood supply for in 
(1) f. A'. Soc. de Biologic, Paris, T. 73-526. Bull. Mus. Hist. Nat., 
Paris Ann., 1911, 492 et seq. 
