THE PARS BUCCALIS OF THE HYPOPHYSIS 9 



apparently gain ingress through the city water supply. Experi- 

 ence during the past three seasons has abundantly justified 

 this 'sterilization,' since infection has been inversely propor- 

 tional to the extent to which this treated water was utilized. 

 Such treatment of the Avater appears to impair in no way the 

 normality of the animals raised therein. 



With the daily feeding of special or check food substances, 

 as has been done in this study, the necessity of removing the 

 uneaten particles which would otherwise putrify has forced us to 

 have special containers manufactured. Our needs were met by 

 having vessels of two sizes cast. One size, made of a gray glazed 

 earthenware, is 12 inches square by 6 inches deep; the other 

 size, made of a gray porcelain, is 6 inches square by 4 inches 

 deep. The water level in either type can be readily changed 

 by an L-tube draining through a hole near the bottom of the 

 container. It was found that from fifty to seventy-five speci- 

 mens eoTild be reared in each of the larger containers without 

 overcrowding and from ten to twenty specimens in each of the 

 smaller ones. The daily cleaning of such containers proved 

 not to be an onerous task when done with a sj^phon cleaning 

 tube fitted with an appropriately shaped inlet. 



Various check and special food substances have been fed: 

 liver, muscle,^ anterior lobe, posterior lobe of the hypophysis, 

 adrenal cortex, adrenal medulla, as well as various extractives 

 and residues of the anterior lobe of the hypophysis. As a check 

 diet, finely ground fresh liver has proved more satisfactory than 

 muscle, since the connective tissue of even finely ground muscle 

 often unites fragments and thus prevents complete deglutition 

 of partly swallowed series of food particles, resulting in the 

 death of the animals. In all cases an abundant supply of boiled 

 lettuce has been furnished. Although liver has proved satis- 

 factory for the normal tadpole, yet by far the most adequate 

 food substance for raising a vigorous, healthy albino is the fresh 

 anterior lobe of the beef hypophysis. With this diet, which 



* Mendel and Osborne ('18) report that the proteins in both muscle and liver 

 are adequate for the needs of nutrition in growth. 



