GROWTH AFFECTED BY FEEDING DUCTLESS GLANDS 333 



b. Thyroid groups. The kidneys reacted to the thyroid feed- 

 ing in a manner similar to that described for the Hver, but to a 

 greater extent (tables 6 to 10). According to Donaldson's 

 method of comparison the increase in the absolute weight of the 

 kidneys is as follows: older females 46.3 per cent, younger fe- 

 males 33.0 per cent, older males 44.4 per cent, and younger 

 males 40.4 per cent (table 10). 



c. Thymus, hypophysis and pineal groups. As shown in 

 tables 6 to 9, the kidneys in the various groups fed on thymus, 

 hjTDophysis and pineal gland show no very constant variations 

 from the controls. The differences are mostly small and are 

 probably due to normal variability. The kidneys of the hypo- 

 physis-fed females average 12 per cent heavier than the con- 

 trols, however, and those of the pineal-fed males average 16 

 per cent under normal weight. 



17. Ovaries {tables 4, 6, 8 and 10) 



a. Controls. In absolute weight, the ovaries appear con- 

 siderably heavier for the younger group, and slightly hea\der 

 for the older group (table 4) than the corresponding ovaries 

 in Donaldson's tables. In relative (percentage) weight, the 

 ovary in the younger groups similarly exceeds the normal found 

 by Jackson ('13), and is about equal in the older group. The 

 ovaries are normally found to be exceedingly variable in weight. 

 This is to be explained partly on account of varying stages of 

 ovulation, and partly to technical difficulties of dissection 

 (Jackson '13). 



b. Thyroid groups. The ovaries in the thyroid groups appear 

 nearly unchanged, the slight differences being very probably 

 due to normal variation. 



c. Thymus, hypophysis, and pineal groups. On comparing 

 the relative weights of the ovaries in these groups, no important 

 or constant changes are found (table 8), except in the pineal- 

 fed group. In these the ovaries appear considerably under 

 weight, as compared with the controls. The decrease in ab- 

 solute weight shown by Donaldson's method is 16.7 and 27.0 



