132 LAWSON G. LOWREY 



fetus, it forms on the average 0. 17 per cent of the total weight. 

 In the adult, it forms about 0.13 per cent. 



Practically the same course of growth is found in the human, 

 although here the spleen is relatively larger than in the pig. The 

 maximum is over 0.4 per cent in the 8th and 9th fetal months. 

 It forms . 43 per cent in live-born infants, and . 25 per cent for 

 the adult (Vierordt). The individual variations would seem to 

 be greater in the human than in the pig. 



Pancreas. {Table 1: fig. 5). Starting with a relative size of 

 0.042 per cent of the total body weight at 42 mm., where it was 

 first observed, the pancreas increases, at first rapidly, then more 

 slowly to a maximum of 0. 19 per cent at the 215 mm. stage. At 

 26 cm., it forms 0.16 per cent of the total weight; in the adult, 

 . 14 per cent. In the pig, the variations in individual size appear 

 very great, due perhaps in part to difficulty in dissecting it out 

 perfectly. During the greater part of fetal life, the pancreas 

 averages about 0. 1 per cent to.0. 13 per cent of the total weight. 



Judging from the data available for comparison, the pancreas 

 is slightly heavier relatively in the pig than in the human through- 

 out the greater portion of fetal life, and has about the same rela- 

 tive size in the adult. 



Suprarenal glands. (Table 1: fig. 5). At 25 mm., the supra- 

 renal glands are readily visible with the dissecting lens, but, 

 owing to their position and attachments, cannot be readily dis- 

 sected out and weighed. 



At 42 mm., the suprarenal glands form about 0. 11 per cent of 

 the total weight. At 58 mm., they form 0.13 per cent of the 

 total, which is the maximum observed relative size. Throughout 

 the later part of fetal life, they average about 0.015 to 0.025 per 

 cent of the total, forming 0.019 per cent in the latest stage exam- 

 ined. In the adult they are very small organs, forming about 

 0.005 per cent of the total. There is no marked difference 

 between the right and left in size. 



In the human fetus, the left suprarenal is usually the larger of 

 the two. During the second month, the suprarenals form about 

 0.3 per cent of the total body volume, increasing to a maximum 

 of . 46 per cent in the third month. At full term they form about 



