218 



THE AMERICAN NATURALIST 



[Vol. LV 



there is added to the thymus, the less marked does the 

 inhibition of growth become; small amounts of thymus 

 added to a normal diet have no effect (33). It is un- 

 knowTi at present which of the food substances necessary 

 for growth are missing, although it is certain that the 

 deficiency of the thymus is not caused by a deficiency in 

 iodine, calcium, sodium or potassium. Many other glands, 

 such as the spleen, prescapular lymph-gland, parathy- 

 roids, and posterior lobe of the hypophysis are more or 

 less deficient in the growth of salamander larv». 



1. Gudernatsch, J. F. 



912. Fiitterungsversuche an Amphibienlarven. Vorl. Mitt. Zen- 



tra'hl. Physiol., XXVI, .323. 

 912. Feeding Experiments on Tadpoles. I. The Influence of Spe- 

 cific Organs Given as Food, on Growth and Differentiation. 

 AreJi. f. Eiitwicl-lungsmech., XXXV, 457. 

 914. Feeding Experiments on Tadpoles. II. A Further Contribu- 



Amer. Jour. Anat., XV, 431. 

 916. Studies on Internal Secretion. IV. Treatment of Tadpoles 

 with Thyroid and Thymus Extracts. Anat. Bee, XI, 357. 

 ernatach, J. F. 



912. Feeding Exp<?riment9 on Tadpoles. I. The Influence of Spe- 



Arch. Entw. Mech., XXXV, 457. 

 tigle, W. W. 



918. The Acceleration of Metamorphosis in Frog Larvae by Thy- 

 roid Feeding, and the Effects upon the Alimentary Tract 

 and Sex Glands. Jour. Exper. Zool, XXIV, 521. 



ry, G. S. 



)18. Effects of the Extirpation of the Thyroid Gland upon Ossifi- 

 cation in Ewia pipi^ns. Jour. Exper. Zool., XXIV, 567. 

 ■nhuth, E. 



nS. Is the Influence of Thymus Feeding upon Development, Meta- 

 morphosis, and Growth Due to a Si>ecific Action of that 

 Gland ? Jour. Exper. Zool., XXV, 135. 



919. Relation between Thyroid Gland, Metamorphosis and Grow-th. 

 Jour. Gen. Physiol., I, 473. 



919. Relation between Metamorphosis and other Developmental 

 Phenomena in Anipliibians. Jour. Gen. PhysioL, I, 525. 



