22 
PHYSIOLOGY: S. HATAI 
20. Colorado Plateaus: (a) High Plateaus of Utah; (b) Uinta Basin; 
(c) Canyon Lands; (d) Navajo section; (e) Grand Canyon sec- 
tion; (f) Datil section. 
21. Basin-and-range province: (a) Oregon lake section; (b) Nevada 
Basin; (c) Sonoran Desert; (d) Salton Trough; (e) Mexican 
Highland; (f) Sacramento section. 
Pacific Mountain System. — 
22. Sierra-Cascade Mountains: (a) Northern Cascade Mountains; (b) 
Middle Cascade Mountains; (c) Southern Cascade Mountains; 
(d) Sierra Nevada. 
23. Pacific Border province: (a) Puget Trough; (b) Olympic Moun- 
tains; (c) Oregon Coast Range; (d) Klamath Mountains; (e) 
California Trough; (f) California Coast Ranges; (g) Los Angeles 
Ranges. 
24. Lower Californian province. 
^ An excellent account of these attempts has been given by Joerg, W. L. G., Assoc. Amer. 
Geogr., Annals, 4, 1914 (55-84), 22 maps. 
^Fenneman, N. M., Assoc. Amer. Geogr., Annals,^, 1914 (84-134), 3 maps. 
ON THE COMPOSITION OF THE MEDUSA. CASSIOPEA XAMACHANA 
AND THE CHANGES IN IT AFTER STARVATION 
By S. Hatai 
TORTUGAS LABORATORY. CARNEGIE INSTITUTION OF WASHINGTON 
Communicated by A.G.Mayer, December 13, 1916 
Cassiopea may be divided into three distinct parts; mouth-organs, 
umbrella and velar margin. Since these three parts dififer not only 
morphologically, but also in their absolute weights, as well as in the 
relative amount of cellular and non-cellular constituents, it was thought 
desirable to study the normal growth of these parts in order to determine 
whether the starving Cassiopea loses weight uniformally or whether 
the loss is dissimilar in the three parts concerned. A large number of 
observations were also made on the undivided Cassiopeas. 
The observations made on the normal Cassiopea may be summarized 
as follows: (1) Relative weights of mouth-organs, umbrella and velar 
margin differ somewhat according to the size of the entire body. (2) 
The water content of the entire body, as well as of different parts, is 
practically identical throughout the animal's life cycle, so far as fol- 
lowed. (3) The percentage of nitrogen in the solids is highest in the 
smallest medusa, and the values decrease progressively with increasing 
bod}^ weight. The percentage of nitrogen is highest in the velar margin 
and decreases in the mouth-organs and umbrella in the order named. 
