SPLENIC DISEASE. 
327 
blood, through the latter organ, and its diminution when the 
portal system is relieved, by discharges from the bowels or 
effusion of blood into the stomach. 
The structural differences and functional peculiarities of the 
liver and spleen are no less important, and call for our careful 
consideration. In the one we have a non-distensible, highly 
organized, and extremely vascular gland ; composed of a 
number of cells — unique in their kind — formed into lobules 
by the minute branches of the portal and hepatic veins, 
hepatic artery and ducts, surrounded by an areolar invest- 
ment, which, in the pig especially, isolates the lobules from 
one another, giving them a polyhedral form, and is con- 
tinuous with the fibrous investment on the external surfaces 
of the organ, elaborating a highly complex fluid out of 
materials which do not pre-exist in the same condition in the 
blood, serving important purposes in the economy. 
In the other we have an easily distensible, highly vascular, 
and very complex organ, containing a peculiar pulp lodged 
in the interstices of a trabecular stroma, also capsules filled 
with nucleated cells, nuclei, and intercellular fluid, traversed 
by blood capillaries, attached to the vessels and surrounded 
by the pulp ; which, wdiile containing collections of red 
blood corpuscles in various conditions, resembles generally 
in nature the matter within the capsules, and which is like- 
wise traversed by fine blood-vessels, performing functions ill 
understood, or at least not definitely agreed on or determined. 
The investing membrane or capsule is peculiar, and worthy 
of notice in this connection ; as upon its nature depends, 
more or less, the frequent and fatal occurrence of this disease 
in ruminants. This in the spleen of the ox is a thick, 
whitish, and opaque membrane, composed to a great extent 
of elastic tissue, and possesses accordingly the physical 
property of elasticity, may be widely stretched without 
laceration, returning readily to its original size as soon as 
the tension is relieved ; but contains few, if any, muscular 
fibres, which are found abundantly in the spleen of the pig, 
dog, and cat, so that it is not endowed with contractility, as 
in the latter. Morrant Baker says : “ In respect to its office, 
recent investigations seem to have furnished us with more 
definite information. In the first place, the large size which 
it gradually acquires towards the termination of the digestive 
process, and the great increase observed about this period in 
the amount of the finely-granular albuminous plasma within 
its parenchyma, and the subsequent gradual decrease of this 
material, seem to indicate that this organ is concerned in 
elaborating the albuminous or formative materials of food, 
