Relation between the Thymus and the Generative Organs. 87 



100 140 180 220 2G0 300 340 



Fig. 6.— Effect of Eemoval of the Thymus on the Weight of the Testes (Prof. Paton's 



data). 



(Vertical, logarithm of the testes-weight in decigrammes ; horizontal, body-weight in 

 grammes. Unbroken line, regression line for normal animals ; broken line, regression 

 line for operated animals. Clear circles, normal animals ; black circles, operated 

 animals.) 



and 24 thymusless animals, were, t being the testes-weight in decigrammes 

 and b the body-weight in grammes : — 



Thymusless log* = (0-00489 ± 0-00043) 5-0-4069 + 0-1065, 



Controls log* = (0-00503 ±0-00025) b- 0-5193 + 0-0608. 



If the three normals and four thymusless whose body-weights are over 

 300 grm. be excluded, the results are : — 



Thymusless log* = (0-00539 + 0-00051) 6-0-5097 + 01203, 



Controls log* = (0-00501 + 0-00030)5-0-5156 + 0-0815. 



The probable errors must not be regarded as too precise, since they are 

 obtained on the assumption of normal correlation, but they are likely to give 

 a fair guide to the possible magnitude of fluctuations. That of the coefficient 

 of the body-weight (the regression of the logarithm of the testes-weight on 

 body-weight) is the known value 



0-6745 . ^Lzr!) ; 



while for the constant term I find the probable error 



0-6745 I ?la-r 2 )+x 2 2 ^'fl-^' 



