23(3 



Messrs. Bateson, Saunders, and Punnett. [Dec. 1, 



(8) The brain of a case of Trypanosomiasis did not show small celled 

 infiltration. 



(9) Animals infected with Trypanosoma Gambiensc show sometimes 

 changes in the nervous system, localised in the grey matter, haemorrhages, 

 lymphocytes, and a few leucocytes in the peri-vascular space : hsemo-lymph 

 glands in large numbers, and sometimes necrosis of the spleen and degenera- 

 tion of the bone marrow. 



(10) Animals infected with Trypanosoma dimorphwnx exhibit similar changes 

 in the nervous system and organs. A far greater deposit of pigment in the 

 lymph glands and in older cases in the spleen is present. 



Further Experiments on Inheritance in Sweet Peas and Stocks : 



Preliminary Account. 



By W. Bateson, F.B.S., E. E. Saunders, and R. C. Punnett. 



(Received December 1, — Read December 7, 1905.) 



Later results have provided expressions which include many of the peculiar 

 phenomena of inheritance already witnessed in sweet peas and stocks. In 

 sweet peas we have shown that purple may occur, as a " reversion," from 

 the cross between two whites, one having long pollen grains, the other 

 round. Similarly in stocks, white glabrous x cream glabrous gives 

 "reversionary" Fi purple hoary. (In both cases the parents are whites, 

 i.e., free from sap-colour, for cream is due to yellow plastids, recessive to 

 colourless plastids.) 



The appearance of coloured flowers is due to the simultaneous presence 

 in the zygote of two factors, belonging to distinct allelomorphic pairs, which 

 may be spoken of as C, c, and E, r, the large letter denoting presence, the 

 small letter the absence of the particular factor. 



Hoariness of stocks is similarly due to the coexistence of two other factors, 

 and the presence of either of these factors is also allelomorphic to its 

 absence. These two pairs are spoken of as H, h, and K, But, though 

 H and K may both be present, no hoariness is produced unless C and E, 

 the colour- factors, are also both present. For the actual development of 

 hoariness four factors are thus required. The existence of white-flowered 

 hoary plants creates a difficulty : but white incana is evidently a coloured 



