248 ARTHUR WILLIAM MEYER 



ditions requises." The same objection urged above applies, to 

 be sure, to these two experiments for in these cases also, the 

 conditions responsible for the formation of accessory spleens 

 before operation may have been responsible for their continued 

 formation after splenectomy unless one assumes as Tizzoni ap- 

 parently did not that these processes are limited entirely to the 

 main spleen for Tizzoni reported the existence of identical path- 

 ological processes — chronic insterstitial splenitis — in accessory 

 spleens. But it is much more likely that Foa was correct when 

 he confirmed Luschka's conclusion that accessory spleens are also 

 found in the presence of wholly normal spleens. 



In a final article Tizzoni reported on twenty-nine dogs in 

 only four of which he found accessory spleens and never more 

 than three in any one animal. The interesting thing in this 

 article is the finding of the same pathological processes in the 

 accessory as in the main spleen and the existence of a zone 

 of infiltration around some of the accessory spleens. Tizzoni 

 again concluded that the findings confirm all his previous con- 

 clusions. 



Although Mosler (26) is usually quoted as having concluded 

 that a new formation of spleens occurs after splenectomy this is 

 a mistake. Out of thirty splenectomies on dogs done by Mosler 

 the great omentum was covered with dark red nodules in only 

 one dog! These nodules which Mosler upon Roth's examina- 

 tion and diagnosis which was based on Vhchow's 'aufgestelten 

 Principien/ called teleangiectatic hemorrhagic lymphomata were 

 noticed ten months after operation. They varied from a lentil 

 to a bean in size and looked like the spleen. Even granting that 

 these nodules were accessory spleens there is absolutely no evi- 

 dence to show that they were formed after or because of splen- 

 ectomy. Mosler did not examine these dogs — or any others — • 

 before operation and facts presented elsewhere make it highly 

 probable that these nodules were present before operation. More- 

 over, Mosler himself emphasized the fact that although Roth 

 found hyperplasia of the mesenteric and of the aggregate lymph 

 nodes in this dog he never saw such things in any of the other 

 twenty-nine. 



