In the yeast cell it accumulates and disappears very rapidly according to the conditions of nutrition and is sometimes so abundant as to fill the cell almost entirely (Errera, 1882, 1895: Wager and Peniston, 1910).
The blood of most species behaves differentially towards precipitants, and it is therefore conceivable that when blood is used as food and is elaborated into special compounds for the nutrition of the reproductive organs of a parasite, these specific or larger differences in the blood of animal hosts may prevent the ripening of the gonads of a widely diffused parasite and only one particular kind of blood prove suitable.
The variable first maxillae are seldom pediform, their function being concerned chiefly with nutrition, sensation and respiration.
Hales (1727I 733) discussed the rotting of wounds, cankers, &c., but much had to be done with the microscope before any real progress was possible, and it is easily intelligible that until the theory of nutrition of the higher plants had been founded by the work of Ingenhouss, Priestley and De Saussure, the way was not even prepared for accurate knowledge of cryptogamic parasites and the diseases they induce.
It may be that in particular cases particular modes of cultivation disfavour the host; or that the soil, climate or seasons do so; but overwhelming evidence exists to show that the principal causes of epidemics reside in circumstances which favor the spread, nutrition and reproduction of the pest, and the lesson to be learnt is, that precautions against the establishment of such favoring conditions must be sought.
For a time after entry they multiply, obtaining the nitrogen necessary for their nutrition and growth from the free nitrogen of the air, the carbohydrate required being supplied by the pea or clover plant in whose tissues they make a home.
In the Principles of Sociology Spencer's most influential ideas have been that of the social organism, of the origination of religion out of the worship of ancestral ghosts, of the natural antagonism between nutrition and reproduction, industrialism and warfare.
It is supposed that these remarkable phenomena have gradually been evoked by difference in the nutrition of the alternating generations.
The developing embryo at the end of the suspensor grows out to a varying extent into the forming endosperm, from which by surface absorption it derives good material for growth; at the same time the suspensor plays a direct part as a carrier of nutrition, and may even develop, where perhaps no endosperm is formed, special absorptive "suspensor roots" which invest the developing embryo, or pass out into the body and coats of the ovule, or even into the placenta.
Our starting-point in this, as in all departments of biological study, must be the biological unit, and it is to the alterations to which this is subject, under varying conditions of nutrition and stimulation, that the science of pathology must apply itself.
Trophic disturbance in the nutrition of the skin may be so great that a slight degree of external pressure or irritation is sufficient to excite even a gangrenous inflammation.
Dutrochet towards the middle of the century, and Liebig's application of chemistry to agriculture and physiology put beyond question the parts played by the atmosphere and the soil in the nutrition of plants.
These salts are sucked up by the roots of plants, and by taking part in the process of nutrition are partly converted into oxalate, tartrate, and other organic salts, which, when the plants are burned, are converted into the carbonate, K 2 CO 3.
And finally, consider how nutrition affects other relative and subjective factors in our lives such as energy level and mood.
Computers, especially computers of the future, will have no trouble handling all the variables that influence nutrition, though there will be millions of them.
If, on the other hand, the endosperm is the product of an act of fertilization as definite as that giving rise to the embryo itself, we have to recognize that twin-plants are produced within the embryo-sac - one, the embryo, which becomes the angiospermous plant, the other, the endosperm, a short-lived, undifferentiated nurse to assist in the nutrition of the former, even as the subsidiary embryos in a pluri-embryonic Gymnosperm may facilitate the nutrition of the dominant one.
38 first, either the marked contrast in the method of nutrition of the generally colourless Bacteriaceae to that of the blue-green Cyanophyceae is regarded as sufficient ground for to recommend it on phylogenetic grounds.
And because agriculture is a technology, subject to technological advance, advances in agriculture will quicken and multiply, leading to improved nutrition and decreased hunger and famine.
So the current frustrating situation, where so many people have such wildly divergent understandings about nutrition, will fade away.
This conception of,the plant as an aggregate or colony of independent vital units governing the nutrition, growth and reproduction of the whole cannot, however, be maintained.
If the flow of arterial blood only is arrested, the part depending upon it for nutrition becomes numb, cold and shrivelled, and the form of mortification known as dry gangrene occurs.
The subtle interplay of everything involved in nutrition is vastly more complex than our minds are able to handle.
All that we have explored in this section—rising incomes, advances in nutrition and genomics, innovations in agricultural technologies—will eventually end hunger.
When the bud is nearly complete, the body-wall of the parent immediately below it becomes perforated, placing the coelenteric cavity of the parent in secondary communication with that of the bud (H), doubtless for the better nutrition of the latter.
The building up and nutrition of the living substance by the foods manufactured or absorbed is properly spoken of as the assimilation of such food.
Experience with epidemics, dearly bought in the past, has shown that one fruitful cause is the laying open to the inroads of some Fungus or insect, hitherto leading a quiet endemic life in the fields and forests, large tracts of its special food, along which it may range rampant without check to its dispersal, nutrition and reproduction.
The movements of bones and muscles were referred to the theory of levers; the process of digestion was regarded as essentially a process of trituration; nutrition and secretion were shown to be dependent upon the tension of the vessels, and so forth.
They are responsible for many important chemical processes which make the soil constituents more available and better adapted to the nutrition of crops.
He showed that the gaseous constituents of the air contribute largely to the nourishment of plants, and that the leaves are the organs which elaborate the food; the importance of leaves in nutrition had been previously pointed out by Malpighi in a short account of nutrition which forms an appendix to his anatomical work.
But the proper nutrition of the conducting substance is indissolubly dependent on the cell branches being in continuity with the cell body and nucleus it contains.
In cases where the embryo has stored reserve food within itself and thus provided for self-nutrition, such endosperm as remains in the seed may take on other functions, for instance, that of water-absorption.