694 HENRY H. DONALDSON 
fall off with anything like the rapidity that it does in man and 
some other mammals. This difference suggests a number of 
questions to answer which it will be necessary to take up the study 
of growth in hibernating mammals. 
LITERATURE CITED 
BrauDIMONT ET St. ANGE 1847 Sur les phenomenes chimiques de l'evolution 
embryonnaire des oiseaux et des batraciens. Annal. de Chim. et de 
Physique, 38rd series, vol. 21. 
vy Bezoup, A. 1857 Untersuchungen iiber die Vertheilung von Wasser, organ- 
ischer Materie und unorganishen Verbindungen in Thierreiche. Ztschr. 
f. wiss. Zool., vol. 8, pp. 487-524. 
Boycorr, A. E. 1904 On the number of nodes of Ranvier in different stages of 
the growth of nerve fibers in the frog. J. of Physiol., vol. 30, pp. 370- 
380. 
Dickerson, Mary C. 1907 The frog book. Doubleday, Page & Co., N. Y. 
Dona.tpson, H. H. 1898 Observations on the weight and length of the central 
nervous system and of the legs in bullfrogs of different sizes. Jour. 
Comp. Neur. Psych., vol. 8, no. 4, pp. 314-335. 
1902 On a formula for determining the weight of the central nervous 
system of the frog from the weight and length of the entire body. 
Decennial publications, University of Chicago, vol. 10. 
1908 The nervous system of the American leopard frog, Rana pipiens, 
compared with that of the European frogs Rana esculenta and Rana tem- 
poraria (fusca). Jour. Comp. Neur. Psych., vol. 18, no. 2, pp. 121- 
149. ; 
1910 Further observations on thenervous system of the American leop- 
ard frog (Rana pipiens) compared with that of the Huropean frogs 
(Rana esculenta and Rana temporaria). Jour. Comp. Neur. Psych., 
vol. 20, no. 1, p. 1-18. 
Donaupson, H. H. anp ScHoEMAKER, D. M. 1900 Observations on the weight 
and length of the central nervous system, and of the legs in frogs of 
different sizes (Rana virescens brach'zcephala Cope). Jour. Comp. 
Neur. Psych., vol. 10, no. 1, pp. 109-132. z 
Fiscuer-Sigwart, H. 1897 Biologische Beobachtungen an unseren Amphibien. 
Vierteljahrsch. d. Naturf. Gesell., Ziirich, vol. 42, Jahrg. 1897. 
Harat, 8. 1911 A formula for determining the total length of the leopard frog 
(R. pipiens) for a given body weight. Anat. Rec., vol. 5, no. 6. 
Mauuinc-HANSsEN, R. 1886 Perioden im Gewicht der Kinder und in der Sonnen- 
wirme. Kopenhagen. 
MoraczEwskI, W. von 1900 Die Zuzammensetzung des Leibes von hungernden 
und blutarmen Fréschen. Arch. Anat. u. Phys., Suppl. Bd. zur phys. 
Abthl. 
ToRELLE, EtteN 1903 The response of the frog to light. Am. J. of Physiol., 
vol. 9, pp. 466-488. 
