On Blood-Platelets. 



467 



rapidly, if the application of radium is discontinued, and the dose has not been 

 too large. 



If by exposure to radium, or by withholding the fat soluble vitamin, the 

 number of platelets has been reduced below a certain critical level — about 

 300,000 for the rat — the resistance of the animal to infection is greatly 

 diminished and infective conditions develop spontaneously. Tbese may lead 

 to a secondary anaemia. The infective conditions may clear up again as the 

 number of platelets is made to increase. 



The blood platelets fulfil an important function in the mechanism of 

 resistance to bacterial infection. Alterations in the local or general resistance 

 to infection are associated with local or general changes in the distribution of 

 the platelets. 



The radium used in these investigations was a loan from the Medical 

 Eesearch Council. 



REFERENCES. 



(1) Cramer and Pringle, 'Phys. Soc. Proc.,' July 27, 1912, p. 11 : ' Journ. of Phys.,' 



vol. 45 ; ' Quart. Journ. Exp. Physiology,' vol. 6, p. 1 (1913). 



(2) Bordet et Delange, ' Annales de lTnstitut Pasteur,' vol. 26, p. 657 (1912). 



(3) Bullock and Cramer, ' Roy. Soc. Proc.,' B, vol. 90, p. 513 (1919). 



(4) Bullock and Cramer, 'VI. Scientific Report Imperial Cancer Research Fund.' 



Taylor and Francis, 1919. 



(5) Gruber and Futaki, 'Munchen. Med. Wochenschr.,' 1907, p. 249 ; 'Deutsche Med. 



"Wochenschr.,' 1907, p. 1588. 



(6) Bull, ' Journ. Exp. Med.,' vol. 20, p. 236 (1914) ; vol. 22, pp. 475 and 484 (1915) ; 



vol. 23, p. 419 (1916) ; vol. 24, p. 25 (1916). 



(7) Delrez et Govaerts, ' Compt, Rend. Soc. de Biol.,' vol. 81, p. 53 (1918). 



(8) Govaerts, ibid., vol. 85, p. 745 (1921). 



(9) Ledingham, 'The Lancet,' 1914, p. 1673 ; vol. 1, p. 311 (1915). 

 (10) Bedson, ' Journ. Path, and Bact.,' vol. 25, p. 94 (1922). 



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