TY - JOUR AU - AB - [N. S. VOL. XXXII. NO. 819 SCIENCE is representing two hundred and and activities. The length directly discussed, body eighty-eight genera and fifty-five families. proportional to food assimilation and is not Students of Canadian birds are fortunate directly by other external factors affected in the possession of this cyclopedia of com- of the water, light such as salt or gas content prehensive and accurate information. It is to the internal or temperature. With respect scarcely less interesting and valuable to the factor, the first generations produced by ornithologists of the United States, who will small helmets but, under ephippial eggs have find in it a larger mass and greater detail of later the same food conditions, generations reliable matter concerning many of our This seems to show will have larger helmets. species than is to be found in any other like the of a " Helmhohepotenz " which presence publication. It is a methodical, careful record has hereditarily fixed so that the size become of data of observation, simply and clearly be modified by food con- of the helmet may written, for the compilation of which the au- can not be controlled ditions, but it entirely thors deserve the TI - Weitere experimentelle Untersuchungen über Artveränderung, speziel über das Wesen quantitativer Artuntershiede bei Daphniden . By R. Woltereck, Vehr. der Deutschen Zool. Gesellsch. 1909. Pp. 110-172, 18 text figures. JF - Science DO - 10.1126/science.32.819.344 DA - 1910-09-09 UR - https://www.deepdyve.com/lp/unpaywall/i-weitere-experimentelle-untersuchungen-ber-artver-nderung-speziel-ber-6kiql1cv8Z DP - DeepDyve ER -