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This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1909 Excerpt:...and is unable to corroborate Greely, but rather shows that a loss of water accompanies the lowering of the temperature, which causes the hydroids to become opaque, without degenerative changes in the cells. 1 As at South Harpswell, Maine, where the temperature of the water seldom rises above 16 C. 1E. g.. Woods Hole, Mass. Tubularia disappears when the temperature of the water reaches 20 C. It reappears again for a time in the fall. 8 Greely, " Further Studies on the Effects of Variations of Temperature on Animal Tissues," Scientific Papers. ' McGill, C, " The Effect of Low Temperature on Hydra," Biol. Bull., Vol. 14, 78. Little success has been had with Tubularia in exhibition tanks. If some means could be devised for keeping the water in such tanks at a temperature, say of 15 C., the writer believes that Tubularia could be maintained in health, as in the sea. The writer has studied Tubularia at the Bureau of Fisheries and the Marine Biological Laboratory, at Woods Hole and at the Harpswell Laboratory. To those in charge of these laboratories, Professors Sumner, Lillie and Neal and to Dr. Kingsley and Professor Lambert, the writer is indebted for much kindness. The work was started at the suggestion of Dr. T. H. Morgan and the writer is grateful to him for generous aid and criticism. College Of The City Of New York, December 15, 1908. PRELIMINARY REPORT ON THE EARLY HISTORY OF THE EGG AND EMBRYO OF CERTAIN HYDROIDS. CORA JIPSON BECKWITH. Within the last few years some of the hydroids (Pennaria, Clava leptostyla, Eudendrium, Tubularia crocca) have been described as differing widely in their processes of maturation, fertilization, and early cleavage from what we have come to think of as typical. Other members of the same group (Tubularia...