68 



Mr. Hainan and Dr. Marshall. 



as greater than 90°, i.e. directed upwards to the left, but where the anatomical 

 axis is distinctly less than 90°, i.e. directed downwards to the left.] 



Corrigenda in Part I, ' Eoy. Soc. Proc./ B, vol. 86. 



Page 512. In the second line of the footnote tan = should read tan a =. 



Page 514. Last line, tan a = — — ^ should read tan a = 2 ^ ^ 



R+L R+L 



Page 520. The record of the right superior lead is placed upside down. The first 

 ventricular wave is actually negative. 



Page 525. The numbers 36 and 47 in the last column (15th and 16th from bottom) 

 should be transposed. 



On the Relation between the Thymus and the Generative Organs 

 and the Influence of these Organs upon Growth. 



By E. T. Halnan and F. H. A. Marshall. (With a Note by G. Udny 



Yule.) 



(Communicated by Prof. J. N. Langley, F.E.S. Eeceived April 4, — 

 Eead June 18, 1914.) 



Calzolari was the first to show that in castrated male animals the absolute 

 weight of the thymus is larger than that of the same gland in normal 

 animals. The experiments were made upon six rabbits, which were 

 castrated when between one and three months old and killed at various 

 periods afterwards up to nine months, each rabbit being compared with a 

 control. Subsequently Henderson carried out .a statistical investigation 

 upon the weight of the thymus in cattle, and showed that in these animals 

 castration caused a persistent growth and a retarded atrophy of the gland. 

 Henderson also records two experiments upon guinea-pigs by Noel Paton, 

 and the results of these are confirmatory of the observations upon cattle. 



The possible reciprocal action of the thymus upon the testis was 

 investigated by Noel Paton, who removed the former organ from 24 young 

 guinea-pigs and killed them when they attained weights varying from 

 115 to 355 grm. These animals were compared with 23 normal guinea-pigs 

 kept as controls. The conclusion reached was that in guinea-pigs below 

 300 grm. (i.e., prior to the time when the thymus usually atrophies) 

 thymectomy is followed by a more rapid growth of the testes. In guinea- 

 pigs above 300 grm. Paton found that the difference in weight of the testes 

 in thymusless and normal animals was not manifest. The figures upon 



