The American Naturalist, Volume 34, Part 1

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Essex Institute, 1900 - Biology

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Page 75 - The Cretaceous formation of the Black Hills as indicated by the fossil plants (with the collaboration of WP Jenney, WM Fontaine, and FH Knowlton).
Page 441 - ... old, migration could become in time a ruling Habit in the life of a last summer's bird, holding it true to route and period of movement. In short, it is believed that the causes of migration are simple facts and not impenetrable mysteries lying beyond the domain of scientific enquiry. Summary. — To sum up the whole matter in a single sentence : It is held that bird migration is a habit evolved by education and inheritance which owe their origin and perpetuation to winter with its failure of...
Page 213 - Mandibles with the rather broad, more or less tridentate, cutting edges meeting squarely behind the large upper lin ; the secondary plate and peculiar equivalent for the molar well developed. First maxillae having the plate of the first joint armed with three spines, that of the third with many. Second maxillae of moderate size, the three free plates very setose. Maxillipeds with the palp rather broad, very setose. Family V. Cirolanidas g'.
Page 201 - Maine.) TYPE LOCALITY. — Hudson Bay. RANGE. — From the southern shores of Hudson Bay south to New Jersey, and in the mountains to North Carolina, west to Iowa and Missouri, and northwest to Alaska.
Page 87 - The Latimer Collection of Antiquities from Porto Rico, in the National Museum at Washington, DC By OTIS T.
Page 123 - ... the trunk which has hence been designated the branchiogenital region. A theory of gill-slits was developed, according to which gillslits arose in the interannular depressions while the gonads were disposed in zones corresponding with the epidermal annulations. The primary function of the gill-slits was the oxygenation of the gonads, their secondary function being the respiration of the individual.
Page 245 - ... consortia, that it is more convenient to treat them as a separate class. In the formation of the thallus the algal cells become enveloped by the mycelium of the fungus in a felted tissue of hyph;e (Fig.
Page 173 - SOME NOTES ON REGENERATION AND REGULATION IN PLANARIANS. FRANK R. LILLIE. I. THE SOURCE OF MATERIAL OF NEW PARTS AND LIMITS OF SIZE. MANY observers have noted the tendency of planarians kept without food to diminish in size. My attention was specially directed to this phenomenon by some experiments undertaken to test the effect of external conditions on the regeneration of Planaria maculata. I had already studied the effect of temperature on the regeneration of this form in conjunction with Mr. Knowlton....
Page 210 - ... with carpus attenuated, hand very large, oblong, finger elongate and curved, immovable, strongly tuberculate within. Thoracic appendages not specialized into an anterior and a posterior series. Marsupium of female formed of eight large lamellae from the four first free segments.
Page 219 - Posterior angles of first thoracic segment prominent or produced, very often acute ; posterior angles of the following segments increasing gradually in length, the first of these very often scarcely prominent, the posterior ones very often produced, abruptly longer than the first. Epimera of the first segments extending beyond the posterior angles of the segment ; posterior ones produced, acute. Nerocila Leach c'.

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