Comentarios de usuarios - Escribir una reseña
No hemos encontrado ninguna reseña en los sitios habituales.
Otras ediciones - Ver todo
acid already amount angle animals appears atomic base become beds bismuth body cause changes character closely color common compared connected considered consists contain continued crystals described determined direction distinct effect elements equal examination existence experiments extended fact feet fishes force formation formula fossils genus give given greater heat important inches increase interesting iron islands known Lake less light limestone limits lines lower magnetic mass means mentioned miles mineral natural nearly North object observed obtained occur organic original pass period plane plants portion position present prism probably produced reference regard relation remains remarkable represented river rocks seen separated side similar species specimens structure substance surface taken temperature tion trace true tube upper weight whole
Página 157 - Illustrations | of the | Birds | of | California, Texas, Oregon, British and | Russian America. | Intended to contain descriptions and figures | of all | North American Birds | not given by former American authors, | and a | General Synopsis of North American Ornithology.
Página iii - Report on the geology of the Lake Superior land district : by JW Foster and JD Whitney, United States Geologists. Part II.
Página 301 - Manual of Natural History for the Use of Travellers ; being a Description of the Families of the Animal and Vegetable Kingdoms, with Remarks on the Practical Study of Geology and Meteorology. To which are appended Directions for Collecting and Preserving. By ARTHUR ADAMS. MRCS ; W.
Página 91 - And in regard to long circuits such as those described, their conducting power cannot be understood, whilst no reference is made to their lateral static induction, or to the conditions of intensity and quantity which then come into play ; especially in the case of short or intermitting currents, for then static and dynamic are continually passing into each other.
Página 381 - In the chick no traces of the kidney are perceptible, according to my own observations, until the end of the fourth or the beginning of the fifth day. The ureter, then, is the part first seen, and consists of a simple tube, the upper part of which sends off branches.
Página 94 - ... the same voltaic source, the same current in the same length of the same wire gives a different result as the intensity is made to vary with -variations of the induction around the wire. The idea of intensity, or the power of overcoming resistance, is as necessary to that of electricity, either static or current, as the idea of pressure is to steam in a boiler, or to air passing through apertures or tubes, and we must have language competent to express these conditions and these ideas.
Página 76 - ... perception of which is deeply connected with our highest appreciation of individual animal life.* A true generation must be regarded as resulting only from the conjugation of two opposite sexes — from a sexual process in which the potential representations of two individuals are united for the elimination of one germ.
Página 340 - ZEALAND. 4. These three peculiarities are shared by all the islands in the south temperate zone (including even Tristan d'Acunha, though placed so close to Africa), between which islands the transportation of seeds is even more unlikely than between the larger masses of land. 5. The plants of the Antarctic islands, which are equally natives of New Zealand, Tasmania, and Australia, are almost invariably found only on the lofty mountains of these countries.
Página 69 - ... as already mentioned. Moreover, these rows of germs, which, at one period, closely resemble in general form the ovaries of some true insects, are not continuous with any uterine or other female organ, and therefore do not at all communicate directly with the external world. On the other hand, they are simply attached to the inner surface of the animal, and their component germs are detached into the abdominal cavity as fast as they are developed, and then escape outwards through a...