546 Veteri7iary Medicine. 



This may be held to take place largely under the influence of the 

 varying force of the blood pressure in the portal vein, but accord- 

 ing to the observations of Roy on dogs and cats, it is also power- 

 fully influenced by muscular and nervous action. He found 

 rhythmic contractions of the organ due to the muscles contained in 

 the capsule and trabeculse, repeating themselves sixty times per 

 hour, and which might be compared to tardy pulsations. He fur- 

 ther found that electric stimulation of the central end of a cut sen- 

 .sory nerve, of the medulla oblongata, or of the peripheral ends of 

 both splanchnics and both vagi caused a rajiid contraction of the 

 spleen. The spleen may thus be looked on not only as a tempo- 

 rary store house for the rich and abundant blood of the portal 

 system of veins during active digestion, but also as a pulsating 

 organ acting under the control of nerve centres in the medulla. 

 That the various ascertained normal functions of this vis-cus ma}- 

 be vicariously performed by others, as shown in animals from 

 which it has been completely extirpated, does not contradict the 

 occurrence of actual disease in the organ, nor the baleful influ- 

 ence of certain of its diseases on the s^'stem at large. 



ANEMIA OF THE SPLEEN. 



General aiiceinia, debility, wasting diseases, starvation, luemorrhage, 

 stimulus to formation of red globules, asphyxia, electricity, cold, quinine, 

 eucalyptus, ergot. Symptoms : lack of eosinophile leucocytes in the 

 blood of a debilitated subject may lead to su.spicion. Treatment : tonic, 

 light, sunshine, pure air, exercise, nutritive food, iron, bitters. 



In ca.ses of general anaemia the spleen is liable to be small, 

 shrunken, wrinkled, and when cut the surface is drier and lighter 

 colored than in the normal condition. This condition may be 

 seen after old standing debilitating diseases, but is common in 

 animals that have lieen reduced by .starvation, just as the opposite 

 condition of hypersemia and enlargement comes of abundance of 

 rich food and an active digestion. It may shrink temporarily as 

 the result of profuse hemorrhage, but Bizzozero and Salvioli 

 found that several days after such less of blood it became en- 



