Relation between the Thymus and the Generative Organs. 89 



21 castrated animals— mean thymus weight, 0557 grm. ; s.d., 01104 grm. 

 27 controls — mean weight of thymus, 0*331 grm. ; s.d., 0-0785 grm. 



The difference is 0*226 grm., and is 1P8 times the probable error of the 

 difference, viz., - 0192. 



In the case of Prof. Paton's data respecting the effect of simultaneous 

 removal of- the thymus and the testes on the rate of growth, the differences 

 observed between operated and control auimals seem to point to definite 

 causation. If his Tables III and IV are pooled together, giving 9 operated 

 animals and 12 controls, the difference between the mean gains in weight 

 (viz., 92'2 and 149 , 2 grm.) is 4'1 times its probable error. For Lot 4 of 

 Table V there are only five animals a side, but the results are unusually 

 uniform. The mean gains in weight are 65 and 120 grm., and the 

 difference 6 - 6 times its probable error. This result seems in direct conflict 

 with Hainan and Marshall's experiments ; they have pointed out above a 

 possible cause for the divergence. 



In the preceding, one or two results in probable errors have been given" 

 without proof. I hope to publish the proof elsewhere shortly. 



, REFERENCES. 



Basch, 1 Jahrb. f. Kiuderheil.,' 1906, p. 64 ; 1908, p. 68. 

 Calzolari, 'Arch. Ital. de Biol.,' vol. 30, p. 71 (1898). 

 Gellm, ' Zeitschr. f. Exp. Path, und Ther.,' vol. 8, p. 71 (1910). 

 Gudernatsch, 'Arch. f. Entwick-Mech.,' vol. 35, p. 457 (1913). 

 Henderson, ' Journ. Physiol.,' vol. 31, p. 222 (1904). 

 Hewer, 'Journ. Physiol.,' vol. 47, p. 479 (1914). 



Klose and Vogt, 'Klinik und Biol, der Thymusdrtise,' Tubingen, 1910. 



Marrassini, 'Arch. Ital. de Biol.,' vol. 53, p. 419 (1910). 



Matti, 'Ergeb. der Inneren Med. und Kinderheil.,' vol. 9, p. 1 (1912). 



Paton, ' Journ. Physiol./ vol. 32, p. 28 (1905). 



Paton, 'Journ. Physiol.,' vol. 42, p. 267 (1911). 



Paton and Goodall, ' Journ. Physiol.,' vol. 31, p. 49 (1904). 



Soli, 'Arch. Ital. de Biol.,' vol. 47, p. 115 (1907). 



Soli, 'Arch. Ital. de Biol.,' vol. 52, p. 353 (1909). 



Squadrini, ' Pathologica,' ami. 2, p. 10 (1910). 



Stotsenburg, ' Journ. Anat. Record,' vol. 7 (1913). 



VOL. LXXXVIII. — B. 



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