6i8 SCIENCE PROGRESS 



(28) Swingle, 1919. /. Exp. Zool., 27, 397. 



(29) Swingle, 1922. Anat. Rec, 23 (Proc), 41 and 100. 



(30) Uhlenhuth, 1919a. /. Gen. Physiol., 1, 23. 



(31) Uhlenhuth, 1919b. Endocrin, 3, 285. 



(32) Uhlenhuth, 1921. Am. Nat., 55, 193. 



(33) WiTSCHi, 1922. Ztsch. Ind. Abst. Vererb., 29, 31. 



(34) Zandren, 1921. Acta Med. Scandin., 54, 323. 



