146 THE UNIVERSITY SCIENCE BULLETIN. 



CONCLUSIONS. 



1. The thymus gland in the fcetal pig is comparatively very 

 large, extending from a point above the upper half or third of the 

 heart to the base of the mandible. In the thorax it consists of a 

 single triangular body, but in the neck region is made up of paired 

 branches which approximately parallel each other. 



2. Sex appears to Have no connection with the percentage of 

 thymus found, except that possibly the values for the females may 

 average a trifle higher than those for the males. 



3. As larger and larger fceti, as regards both weight and length, 

 are examined, the percentage of thymus by weight increases fairly 

 steadily and rather uniformly. 



4. Fceti tend to have the same size thymus as the average of pigs 

 in their litter, regardless of individual size. No parallelism appar- 

 ently exists between the small and large size, respectively, of under- 

 developed and overdeveloped pigs, and the percentage of thymus by 

 weight. Perhaps further work on this one question might bring a 

 reversal of opinion, but the data obtained so far point to the state- 

 ment made above. 



5. Figures of percentage of thymus by length, while not very 

 reliable, show that this percentage increases as larger and larger 

 foeti are examined. Such increase, however, does not seem to be as 

 uniform as that of the percentage by weight. 



It is a pleasure to express here our appreciation of the help kindly 

 given by Prof. W. J. Baumgartner in the preparation of this bit of 

 work. It was at his suggestion that it was undertaken and by his 

 guidance that it was carried out. Whatever of merit it has is due' 

 in large measure to him. 



LITERATURE CITED. 



1. Matti, H. 1913. Ergebnisse der Innere Med. u. Kinderheil., Bd. 10. (Quoted 



by Paton, D. Noel, in "The Nervous and Chemical Regulators of Meta- 

 bolism": Macmillan & Co., Ltd., London: 1913; pp. 116-117.) 



2. Basch, K. 1908-1908. Jahrbuch f. Kinderheil. (Quoted by Paton, D. Noel, 



in "The Nervous and 'Chemical Regulators of Metabolism": Mac- 

 millan & Co., Ltd.; London: 1913; p. 114. Also by Biedl, Dr. Artur, in 

 "The Internal Secretary Organs: Their Physiology and Pathology": 

 Trans, by Linda Forster; London: John Bale Sons & Danielsson, Ltd., 

 1913; pp. 117-120.) 



3. Badertscher, J. A. 1915. Development of the Thymus in the Pig. I: Mor- 



phogenesis. Am. Jour. Anat., vol. 17, No. 3, pp. 317-339. 



4. Hatai, S. 1914. On the Weight of the Thymus Gland of the Albino Rat 



{Mus norvegicus albinus) According to Age. Am,. Jour. Anat., vol. 16, 

 No. 2, pp. 251-257. 



