Rivers of James Island, South Carolina, has resulted in the production of disease-resistant races.
The exposed strata are in large part resistant sandstones.
- The method employed is to select, for seed purposes, plants which are resistant to the particular disease.
The substance is very resistant to the action of chemical reagents, to digestion, and possibly belongs to the glyco-proteids.
Owing to greater care on the part of growers, and the introduction of FrenchAmerican resistant stocks to replace vines attacked by the phylloxera, the wines in the early years of the 10th century again acquired a limited sale in England.
Cholera and typhoid organisms are less resistant, and are killed more quickly than tubercle bacilli at the above temperatures.
In 1953, he developed a method to make strains of wheat highly resistant to a single form of rust.
Calmette and Fraser found that when small doses of snake venom, insufficient to cause death, are injected into an animal, temporary disturbance is produced; but after a few days the animal recovers, and a larger dose is then required to produce any symptoms. By gradually increasing the dose the animal becomes more and more resistant, until at last a dose fifty times as great as that which would at first have produced immediate death can be injected without doing the animal any harm.
Probably by unconscious selection of surviving plants through long ages this type has been evolved in Guatemala, and experiments have been made to develop weevil-resistant races in the United States.
They are the most resistant to unfavourable conditions of environment, and are able, by a process of parthenogenesis, to give rise to ordinary, indifferent forms again, which can repopulate the gnat.
New, disease resistant trees are bringing back the splendor of what has been called one of the prettiest towns in New England.
Special interest attaches to experiments made in the United States to endeavour to raise races of cotton resistant to the boll weevil.
Thus he says that the silver which has been changed into gold by the projection of the red elixir is not rendered resistant to the agents which affect silver but not gold, and Albertus Magnus in his De Mineralibus - the De Alchemia attributed to him is spurious - states that alchemy cannot change species but merely imitates them - for instance, colours a metal white to make it resemble silver or yellow to give it the appearance of gold.
Other woods, beautiful and precious, include guayacan (Guaiacum sanctum), baria (varia, Cordia gerascanthoides) - the fragrant, hard-wood Spanish elm - the quiebra-hacha (Copaifera hymenofolia), which three are of wonderful lasting qualities; the jiqui (Malpighia obovata), acana (Achras disecta, Bassia albescens), caigaran (or caguairan, Hymenaea floribunda), and the dagame (Calicophyllum candidissi- mum), which four, like the culla, are all wonderfully resistant to humidity; the caimatillo (Chrysophyllum oliviforme), the yaya (or yayajabico, yayabito: Erythalis fructicosa, Bocagea virgata, Guateria virgata, Asimina Blaini), a magnificent construction wood; the maboa (Cameraria latifolia) and the jocuma (jocum: Sideroxylon mastichodendron, Bumelia saticifolia), all of individual beauties and qualities.
It has, in fact, become metamorphosed into a resistant supporting structure resembling in some respects the notochord of the true Chordata, but probably not directly comparable with the latter structure, being related to it solely by way of substitution.
In addition, the great majority have also another method of reproduction, for increasing the number of the parasites in any individual host; this is distinguished as multiplicative or endogenous reproduction, from the propagative or exogenous method (by means of the resistant spores), which serves for the infection of fresh hosts and secures the dissemination and survival of the species.
This lowland area, due to the non-resistant character of the strata,.
The requirements of an elongate body moving through the resistant medium of water are met by the evolution of similar entrant and exit curves, and the bodies of most swiftly moving aquatic animals evolve into forms resembling the hulls of modern sailing yachts (Bashford Dean).
By a resistant Cretaceous limestone, which dips gently seaward; its scalloped inland-facing escarpment overlooks a denuded central prairie region of irregular structure and form; its gentle coastward slope (16 ft.
The results of the first cycle of erosion are seen in the widespread exposure of the resistant Carboniferous limestone as a broad platform in the south-western area of greater uplift through central Arizona, where the higher formations were worn away; and in the development of a series of huge, south-facing, retreating escarpments of irregular outline on the edges of the higher formations farther north.
The till is presumably made in part of preglacial soils, but it is more largely composed of rock waste mechanically comminuted by the crccpiiig ice sheets; although the crystalline rocks from Canada and some of the more resistant stratified rocks south of the Great Lakes occur as boulders and stones, a great part of the till has been crushed and ground to a clayey texture.
The surface is shown to be a plain of degradation by a gradual ascent here and there to the crest of a ragged escarpment, the cuesta-remnant of a resistant stratum; and by the presence of lava-capped mesas and dike-ridges, surmounting the general level by 500 ft.
Each escarpment stands forth where a resistant formation overlies a weaker one; each escarpment is separated from the next higher one by a broad step of weaker strata.
Turning now to instances of the opposite kind, it is known that silkworms which spin colourless cocoons are more resistant to the attacks of a certain deadly fungus than are those which spin the yellow ones.
This connexion of isomerism with resistant linking, and of this with high valency, explains, in considerable measure, why inorganic compounds afforded, as a rule, no phenomena of this kind until the systematic investigation of metallic compounds by Werner brought to light many instances of isomerism in inorganic compounds.
He was, moreover, not only a non-resistant but also an opponent of all political systems based on force.
Non-myelinate nerve fibres are as resistant to fatigue as are the myelinate.
Trend to crustal deformations which in very early geological time gave a beginning to what later came to be the Appalachian mountain system; but this system had its climax of deformation so long ago (probably in Permian time) that it has since then been very generally reduced to moderate or low relief, and owes its present altitude either to renewed elevations along the earlier lines or to the survival of the most resistant rocks as residual mountains.
The dove of thought falls lifeless if the resistant atmosphere of " the given " be withdrawn (Critique of Pure Reason, ed.
The bacillus is non-resistant and easily killed by heat and germicide substances, particularly acids.
Of the lower animals, mice, rats, guinea-pigs, rabbits, squirrels and monkeys are susceptible to the bacillus; horses, cattle, sheep, goats, pigs, dogs and cats are more or less resistant, but cats and dogs have been known to die of plague (Oporto, Daman, Cutch and Poona).
The belts of non-resistant rock have been worn away, leaving longitudinal valleys separated by hard rock ridges.
Many remedies for this disease have been suggested, including total submersion of the vineyards, the use of carbon bisulphide for spraying, and of copper salts, but there appears to be little doubt that a really serious epidemic can only be dealt with by systematic destruction of the vines, followed by replanting with resistant varieties.
This, of course, naturally leads to the production of a wine somewhat different in character to that produced before the epidemic, but this difficulty may be overcome to some extent, as it was in the Bordeaux vineyards, by grafting ancient stock on the roots of new and resistant vines.
In spite of the many efforts in the direction of obtaining a resistant variety no great measure of success has been attained.
More remarkable still, animals inoculated with such " attenuated " bacilli proved to be curiously resistant to the deadly effects of subsequent inoculations of the non-attenuated form.
The swollen cell-walls - in some cases consists mainly of cellulose, in others chiefly of a proteid substance; the matrix in some cases is horny and resistant, in others more like a thick solution of gum.
A The spores are capable of germination at once, or they may be kept for months and even years, and are very resistant against desiccation, heat and cold, &c. In a suitable medium and at a proper temperature the germination is completed in a few hours.
Many of them, probably also of proteid nature, are much more resistant to heat; thus the intracellular toxins of the tubercle bacillus retain certain of their effects even after exposure to ioo° C. Like the extracellular toxins they may be of remarkable potency; for example, fever is produced in the human subject by the injection into the blood of an extremely minute quantity of dead typhoid bacilli.
He was not, moreover, like his great leader, a non-resistant, nor was he, on the other hand, like John Brown, borne on by irresistible necessity to overt action.
Quartz being a mineral very resistant to weathering agencies, it forms the bulk of sands and sandstones; and when the sand grains are cemented together by a later deposit of secondary quartz a rock known as quartzite results.
Sorghum and kafir corn are also excellent, and broom-corn fairly good, as drought-resistant crops; the last, which is of lessening importance, is localized in Cass, Saunders and Polk counties.
Or S.E.; in this band of weak rocks were several sheets of hard igneous rock (trap) inclined from the horizontal several degrees, and so resistant that they were not removed but remained to form the " trap ridges " such as West Rock Ridge near New Haven and the Hanging Hills of Meriden.
These crystals are extremely resistant to absorption, are found in old blood clots, and have been known to persist in old cerebral haemorrhages after many years.
A plant or animal in perfect health is more resistant to parasitical invasion than one which is ill-nourished and weakly.
But in the derivant valley peneplains developed in the present cycle of denudation, and there are residual summits also; in the Connecticut Valley trap ridges, of which Mt Tom and Mt Holyoke are the best examples; at Mt Holyoke, lava necks; occasionally in the lowlands, ridges of resistant sandstone, like Deerfield Mountain near Northampton; in the Berkshire Valley, summits of resistant schists, like Greylock, the highest summit in the state.
Here, partly because of elevation, and partly because of the resistant nature of the Catskill sandstones, dissection has so sculptured the plateau as to carve it into a mountainous mass which is generally known as the Catskill mountains.
Trend to crustal deformations which in very early geological time gave a beginning to what later came to be the Appalachian mountain system; but this system had Its climax of deformation so long ago (probably in Permian time) that it has since then been very generally reduced to moderate or low relief, and owes its present altitude either to renewed elevations along the earlier lines or to the survival of the most resistant rocks as residual mountains.
When the peneplain was uplifted the weaker strata were worn down almost to a lowland of a second generation, while the resistant sandstones, of which there a1~- three chief members, retained a great part of their new-gained altitude in the form of long, narrow, even-crested ridges, well deserving of the name of Endless Motintains given them by the Indians, but here and there bending sharply in peculiar zigzags which give this Alleghany section of the mountains an unusual individuality.
The height and massiveness of the mountains decrease to the south-west, where the piedmont belt sweeps westward around them in western Georgia and eastern Alabama Some of the residual mountains hereabouts are reduced to a mere skeleton or framework by the retrogressive penetration of widening valleys between wasting spurs; the very type of vanishing forms, Certain districts within the mountains, apparently consisting of less resistant crystalline rocks, have been reduced to basin-like peneplains in the same time that served only to grade the slopes and subdue the summits of the neighboring mountains of more resistant rocks; the best example of this kind is the Asheville peneplain in North Carolina, measuring about 40 by 20 m.
The feature referred to results from the occurrence here of a weak basal formation of clay overlaid by more resistant sandy strata; the clay belt has been stripped for a score or more of miles from its original inland overlap, and worn down in a longitudinal inner lowland, while the sandy belt retains a significant altitude of 200 or 300 ft.
In certain parts of the plateau there are narrow anticlinal uplifts, an outlying effect of mountain-making compression; here a ridge rises if the exposed strata are resistant, as in Chestnut ridge of western Pennsylvania; but here a valley is excavated if the exposed strata are weak, as in Sequatchie Valley, a long narrow trough which cuts off a strip of the plateau from its greater body in Tennessee.
When the two lowlands are traced eastward they become confluent after the Niagara limestone has faded away in central New York, and the single lowland is continued under the name of Mohawk Valley, an east-west longitudinal depression that has been eroded on a belt of relatively weak strata between the resistant crystalline rocks of the Adirondacks on the north and the northern escarpment of the Appalachian plateau (Catskills-Helderbergs) on the south; forming a pathway of great historic and economic importance between the Atlantic seaports and the interior.
In Wisconsin the inner lowland presents an interesting feature in a knob of resistant quartzites, known as Baraboo Ridge, rising from the buried oldland floor through the partly denuded cover of lower Palaeozoic strata.
As is always the case in the broad denudation of the gently inclined strata of such plains, the weaker layers are worn down in sub-parallel belts of lower land between the oldiand and the belts of more resistant strata, which rise in uplands.
To inorganic acids, except hydrochloric, it is highly resistant, ranking well with tin in this respect; but alkalis dissolve it quickly.
More indirect methods, such as the grafting of less resistant scions on more vigorous stocks, of raising special late or early varieties by crossing or selection, and so on, have also met with success; but it must be understood that resistant in such cases usually means that some peculiarity of quick growth, early ripening or other life-feature in the plant is for the time being taken advantage of.