The Journal of the Linnean Society: Zoology, Հատոր 20The Society, 1890 |
Այլ խմբագրություններ - View all
The Journal of the Linnean Society: Zoology, Հատոր 31 Linnean Society of London Ամբողջությամբ դիտվող - 1915 |
Common terms and phrases
abdomen Abdominis segmento anali anal segment angle antennæ ants apex AULACOPHORA basal basilar space birds bone broad as long carapace cells character colour concave convex coxæ Dero dilated posteriorly disk divergent evolution dorsal Elytra elytron excavated Fabr female fertility fish flava flavis flavous form of Segregation fovea Frank Crisp genus Geococcyx half-breeds infra basin insect intermedio Islands joint labrum length leviter LINN lobo intermedio Loch Loch-Leven trout male margin Medit middle millim minutely punctured Natural Selection nearly straight nest nigris nitida Norway obliquely oblong observed obtuse outer ovicell pair Passerine paullo pectore peristome plate posterior postice ampliata postice paullo ampliata Prepotential produced Prof profunde punctatis Pure-breeds Scutellum segmento anali apice segmento anali trilobato Segregate Fecundity Segregation separate setæ side species specimens spines statoblast sulcation suture thickened Thorax Thorax nearly twice tibiæ transversely transversim sulcato Trochilus Trogon twice as broad vertebræ vomer
Սիրված հատվածներ
Էջ 196 - The view maintained in the following paper is I believe in better accord with the fundamental principle that " Unlike units of an aggregate are sorted into their kinds and parted when uniformly subject to the same incident forces,"t as is also the teaching of Spencer's "Principles of Biology," in one passage; for I have recently discovered that in a single paragraph of this work it is maintained that while exposed to the same external conditions, the members of the same species may be increasingly...
Էջ 234 - Intergeneratiou is prevented, and Segeneration is the result, either as Segregation, or as Separation that is gradually transformed into Segregation. (a) CONJUNCTIONAL SEGREGATION. Conjunctional Segregation is Segregation arising from the instincts by which organisms seek each other and hold together in more or less compact communities, or from the powers of growth and segmentation in connection with self-fertilization, through which similar results are gained.
Էջ 192 - World," published in The Chinese Recorder (Shaughai), July, 1885, 1 use the following language: " We see_what natural selection can not explain by considering the nature of the process. The survival of the fittest results in the separate breeding of the fittest, and therefore in the increasing fitness of successive generations of survivors; but how can it account for the division of the survivors of one stock, occupying one country, into...
Էջ 265 - Table XVI were fertilized with pollen from the same flower; and the seedlings raised from them (great-grandchildren of Hero) formed the ninth selffertilized generation. Several other flowers were crossed with pollen from another grandchild, so that they may be considered as the offspring of brothers and sisters, and the seedlings thus raised may be called the inter-crossed great-grandchildren. And lastly other flowers were fertilized with pollen from a distinct stock, and the seedlings thus raised...
Էջ 268 - ... where he staid, three have died leaving widows without male children and with only one or two little girls between the three. The fourth has children of both sexes; but they suffer from affections of the chest and from rheumatism. Mr. Batchelor, whose opportunities for observation have been unusually great, concurs in considering this explanation as sufficient as it is simple. There are scores of mixed marriages every year. There are numerous half-breeds born of these marriages. But the second...
Էջ 233 - ... in the same district. The form of Segregation that precedes Fertilizational Segregation, producing the conditions on which it depends, must, from the nature of the case, be Local Segregation. Chronal and Impregnational Segregation, when imperfectly established, might be fortified by Fertilizational Segregation ; but, in the case of plants, these are all dependent on previous Local Segregation. (e) ARTIFICIAL SEGREGATION. Artificial Segregation is Segregation arising from the relations in which...
Էջ 65 - Park was swarming with people of all kinds, walking in all directions, I took my terrier (which I knew had a splendid nose, and could track me for miles) along the walk, and, when his attention was diverted by a strange dog, I suddenly made a number of zigzags across the Broad Walk, then stood on a seat, and watched the terrier. Finding I had not continued in the direction I was going when he left me, he went to the place where he had last seen me, and there, picking up my scent, tracked my footsteps...
Էջ 266 - ... that they may be considered as the offspring of brothers and sisters, and the seedlings thus raised may be called the inter-crossed great-grandchildren. And lastly other flowers were fertilized with pollen from a distinct stock, and the seedlings thus raised may be called the Colchester-crossed great-grandchildren. In my anxiety to see what the result would be I unfortunately planted the three lots of seeds (after they had germinated on sand) in the hothouse in the middle of winter, and in consequence...
Էջ 228 - ... years of cyclical separation after the thirteen-year race was first formed, this race should become modified in the season of its appearing, there would after that be no mingling of race, though brought together in the same districts. This would be seasonal segregation, which we shall consider in the next section ; but what is of special...
Էջ 272 - Institutional segregation. Institutional segregation is the reflexive form of rational segregation. It is produced by the rational purposes of man embodied in institutions that prevent free inter-generation between the different parts of the same race. As the principal object of the present paper is to call attention to the causes of segregation acting independently of effort and contrivance directed by man to that end, it will be sufficient to enumerate some of the more prominent forms under which...