144 Zoology 



HARVEY, E. N. The Chemistry of Light-production in Luminous Organisms. 63 



pages, i fig. 

 HARVEY, ETHEL BROWNE. A Physiological Study of Specific Gravity and of 



Luminescence in Noctiluca, with Special Reference to Anesthesia. 18 pages. 

 TREADWELL, A. L. Polychartous Annelids from Florida, Porto Rico, Bermuda, 



and the Bahamas. 13 pages, 3 plates. 



JORDAN, H. E. Microscopic Structure of Striped Muscle of Limulus. 17 pages, 3 pis. 

 JORDAN, H. E. Hemopoiesis in the Mongoose Embryo, with special reference to 



the Activity of the Endothelium, including that of the Yolk-sac, n pp., 4 pis. 

 JORDAN, H. E. Embryonic History of the Germ-cells of the Loggerhead Turtle, 



Caretto caretta. 31 pages, 6 plates. 

 JORDAN, H. E. Atresia of the Esophagus in the Loggerhead Turtle Embryo, 



Caretta caretta, a Normal Development Condition. 15 pages, 4 plates. 



Mayer finds that the temperature coefficient for rate of nerve-conduction in 

 Cassiopea is 2.5 as great as that of the electrical conductivity of the sea-water 

 surrounding the nerve. The rate of nerve-conduction appears to be proportional to 

 the degree of ionizations of the sodium calcium and potassium surrounding the 

 nerve, and the decline in rate is the same whether we dilute sea-water with distilled 

 water or with 0.415 molecular magnesium chloride, although the electrical conduc- 

 tivity is widely different in the two cases. 



McClendon, Gault, and Mulholland find that thymolsulphophthalein is a good 

 indicator for testing the alkalinity of sea-water and that the PH of sea-water is 

 practically independent of salinity or temperature between 20 and 30 C. They 

 discuss the CO2 content and buffer value of sea-water under different conditions 

 and show how the oxygen-content and CO2 tension may be determined from the 

 PH. New apparatus for determining hydrogen-ion concentration is described. 



Goldfarb shows that in sea-urchins the females display individual character- 

 istics, the eggs from some females having a high percentage of cleavage while others 

 produce eggs with a low percentage of cleavage. Similarly a male may be efficient 

 in fertilizing the eggs of certain females but relatively inefficient with other females. 

 High cleavage is correlated with normal size, globular form, large jelly count, and 

 rapid membrane formation, while low cleavage is associated with elliptical eggs 

 and a low percentage of intact jelly envelopes. The eggs differ according to their 

 physiologic state, which may be determined by definite tests. 



Phillips finds that the tissues of certain mollusks from Tortugas contain large 

 and variable amounts of copper as well as traces of zinc, iron, manganese and lead. 



Hatai determines the composition of the body substance of the jellyfish Cas- 

 siopea xamachana and finds that when the animal starves the percentage of nitrogen 

 in its tissues increases, becoming higher than that in the bodies of normal indi- 

 viduals of the same size. 



Clark studies the habits and reactions of a crinoid Tropiometra from Tobago, 

 British West Indies, showing that it is remarkably insensitive to light, temperature, 

 and salinity and is thus well suited to life in an aquarium and a good object upon 

 which to perform experiments in embryology. 



Gary finds that the presence of the marginal sense-organs in Cassiopea causes 

 the initial stages of regeneration to be more rapid than they are if sense-organs 

 be absent. Paralyzed but activated disks regenerate more rapidly than paralyzed 

 disks which are not activated. Between 23 to 33 C. the rate of nerve-conduction 

 doubles for 10 rise in temperature, the curve being practically a straight line. 

 When an area activated by a single sense-organ is reduced to one-sixteenth its 

 original size its pulsations per unit time are reduced to one-half the original rate, 

 and beyond this the reduction in rate follows nearly the same ratio as the reduc- 

 tion in area. The sense-organs exert some sort of trophic influence over the 

 metabolic activities of the medusa. 



Harvey studies the chemistry of light-production in luminous organisms. He 

 finds that two substances may be conserved in light production, one a colloid and 

 probably a protein, and the other a crystalloid. The colloidal substance, "pho- 

 togenin," is oxidizable and produces light in the presence of free oxygen, provided 

 the crystalloid substance "photogenin" be .present. Photophelein is widely dis- 

 seminated in the bodies of animals, while "photogenin" is found only in the lumi- 

 nous organs. Neither of the two are soluble in fat solvents. 



Ethel Browne Harvey shows that the specific gravity of Noctiluca is less than 

 that of sea-water, due to their salt-content being less than that of sea-water. They 

 can readjust this condition if placed in brackish water and thus again rise to the 



