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Scientific Proceedings (128) 



they are found to be more numerous in the dark-adapted retina 

 than in the light-adapted one, the extent of their presence is more 

 or less in correspondence with the conditions responsible for the 

 regeneration and the bleaching of visual purple. 



When sections of light-adapted eyes of field mice are com- 

 pared with sections of dark-adapted ones, the droplets occur in 

 considerably reduced numbers in the sections of the light eye as 

 compared with those in the dark eye; and the histological com- 

 parison corresponds closely with that found in the gecko eye 

 under the same conditions. However, a comparative study of 

 light and dark-adapted eyes of Eremias (a diurnal lizard possess- 

 ing cones only) shows a total absence of these droplets under 

 both conditions. 



The exclusive presence of these droplets in rod retinae, as well 

 as the difference which exists between eyes kept in darkness and 

 those exposed to light, is highly suggestive that they are con- 

 cerned with the appearance and disappearance of visual purple 

 under the two respective conditions, although it would be pre- 

 mature to say definitely that they represent a histological pic- 

 ture of this pigment. 



A more complete account of these experiments and of addi- 

 tional ones will be forthcoming. 



The intermediate host of schistosoma japonicum in China. 



105 (2065) 



By HENRY EDMUND MELENEY, and ERNEST CARROLL FAUST. 



[From the Parasitology Laboratory, Department of Pathology, 

 Peking Union Medical College, Peking, China.] 



The snail which acts as the intermediate host of Schistosoma 

 japonicum in Japan has been known since 1913 to be Blanfordia 

 nosophora. No intermediate host for the parasite has heretofore 

 been described for China. We selected the endemic region about 

 Soochow, in Kiangsu Province, for our search. Our method 



