Scientific Proceedings. 



127 



So far only one has been successfuly inoculated. A relatively 

 large dose was injected and the incubation period was twelve 

 days. Three other mice were observed for six, ten and twelve 

 days, respectively, after inoculation without showing a parasite. 



Similar spirochetes have been described by Carter (in rat), 

 Lingard (in bandicoot, Mus giganteus), by Nicolle and Comte (in 

 bat), by Wenyon and by Breinl and Kinghorn (in house mouse) ; 

 all these in the circulating blood. Borrel and Gaylord have de- 

 scribed spiral organisms in mouse carcinomata, and one of the 

 forms found by Borrel has been shown by Wenyon to be identical 

 with his Spirochceta muris found in the blood of mice. Morpho- 

 logically the parasite found here in the rat is apparently identical 

 with this one of Borrel and Wenyon. Its behavior in animals is 

 somewhat different. Therefore, I tentatively suggest for it the 

 name Spirochceta maris, var. Virginiana, following the principle 

 suggested by Calkins. 1 Its specific relation to that organism must 

 be left for further work to determine. 



89 (232) 



Experimental ligation of splenic and portal veins, with the 

 aim of producing a form of splenic anemia. 



By ALDRED S. WARTHIN. 



[_From the Pathological Laboratory, University of Michigan. ,] 



From the pathological study of four cases of splenic anemia 

 showing partial or complete obstruction of splenic or portal veins 

 due to old thrombophlebitis, the writer was led to believe that the 

 splenic enlargement (fibrosis) and the clinical picture of splenic 

 anemia might be produced experimentally in animals. During the 

 last two years he has carried on a series of observations upon 

 dogs whose splenic veins had been ligated at varying distances 

 from that organ. Briefly, the results have been as follows : 



In dogs examined from one week to three months after the 

 operation the spleen was found greatly enlarged, firm and dark in 

 color. This enlargement reached its extreme about four weeks 

 after the ligation. 



1 Calkins : Journal of Infectious Diseases, April, 10, 1907. 



