A bitter principle to which the name of quercin has been applied by Gerber, its discoverer, has also been detected in the acorn of the common oak; the nutritive portion seems chiefly a form of starch.
- Diagram of Tubularia entiated into nutritive and indivisa.
In this way the hydroid colony becomes composed of two portions of different function, the nutritive " trophosome," composed of non-sexual polyps, and the reproductive " gonosome," composed of sexual medusaindividuals, which never exercise a nutritive function while attached to the colony.
5), the blastostyles gradually lose their nutritive function and the organs connected with it; the mouth and tentacles disappear, and the blastostyle obtains the nutriment necessary for its activity by way of the coenosarc. In the Calyptoblastea, where the polyps are protected by special capsules of the perisarc, the gonothecae enclosing the blastostyles differ from the hydrothecae protecting the hydranths (fig.
In other colonies the two functions of the nutritive polyp, namely, capture and digestion of food, may be shared between different FIG.
Brooks, on the other hand, as stated above, regards the medusa as the older type and looks upon both polyp and medusa, in the Hydromedusae, as derived from a free-swimming or floating actinula, the polyp being thus merely a fixed nutritive stage, possessing secondarily acquired powers of multiplication by budding.
SUB-ORDER HYDROIDEA CALYPTOBLASTEA (LEPTOsome with polyps always differentiated into nutritive and reproductive individuals(blastostyles) enclosed in hydrothecae and gonothecae respectively; with sympodial type of budding.
The calyptoblastic polyp of the nutritive type is very uniform in character, its tendency to variation being limited, as it were, by the enclosing hydrotheca.
The medusa-buds, as already stated, are always produced from blastostyles, reduced non-nutritive polyps without mouth or tentacles.
An apparent, but not real, exception is Halecium halecinum, in which the blastostyle is produced from the side of a nutritive polyp, and both are enclosed in a common theca without a partition between them (Allman  p. 50, fig.
It consists of a hollow tube, or tubes, of which the wall is made up of the two body-layers, ectoderm and endoderm, and the cavity is a continuation of the digestive cavities of the nutritive and other appendages, i.e.
The cormus is always differentiated into two parts; an upper portion termed the nectosome, in which the appendages are locomotor or hydrostatic in function, that is to say, serve for swimming or floating; and a lower portion termed the siphosome, bearing appendages which are nutritive, reproductive or simply protective in function.
Siphons or nutritive appendages, from which the order takes its.
A cormidium may contain a single nutritive siphon (" monogastric ") or several siphons (" polygastric ").
The polyp-individuals form the nutritive siphosome or trophosome.
Even in the higher flowering plants, in which the processes of the absorption of substances from the environment has been most fully studied, there is a stage in their life in which the nutritive processes approximate very closely to those of the group last mentioned.
Its nutritive pabulum is supplied to it in the shape of certain complex organic substances which have been stored in some part or other of the seed, sometimes even in its own tissues, by the parent plant from which it springs.
When the tuber of a potato begins to germinate the shoots which it puts out derive their food from the accumulated store of nutritive material which has been laid up in the cells of the tuber.
Identity of the Food of Animals and Plants.rt is evidently to the actual seats of consumption of food, and of consequent nutrition and increase of living substance, that we should turn when we wish to inquire what are the nutritive materials of plants.
They are mainly carbohydrates such as starch and sugar, proteids in the form of globulins or albumoses, and in many cases fats and oils, while certain other bodies of similar nutritive value are less widely distributed.
The differences between the nutritive processes of the animal and the plant are not therefore fundamental, as they were formerly held to be.
Differences connected with the mode of supply of nutritive material do exist, but they are mainly correlated with the structure of the organisms, which makes the method of absorption different.
Certain Algae have been found capable of forming nutritive carbohydrates in darkness, when supplied with a compound of this body with sodium-hydrogen-sulphite.
The independence of the two is suggested by the fact that fungi can live, thrive and grow in nutritive media which contain carbohydrates together with certain salts of ammonia, but which are free from proteids.
The discovery of the widespread occurrence of this mycorhizal symbiosis must be neld to be one of the most important results of research upon the nutritive processes of plants during the closing decade of the 19th century.
The growth of such a cell will be found to depend mainly upon five conditions: (I) There must be a supply of nutritive or plastic materials, at the expense of which the increase of its living substance can take place, and which supply the needed potential energy.
\Vith the water it takes in the various nutritive substances which the former contains in solution.
The growth or increase of the protoplasm at the expense of the nutritive matter for a time keeps pace with the increased size of the cell, but by and by it becomes vacuolated as more and more water is attracted into the interior.
Deficiency of nutritive salts, especially nitrates and phosphates; the presence of poisonous salts of iron, copper, &c., or (in the soil about the roots of trees in towns) of coal-gas and so forth.
Thus, in a phanerogam, the sepals, petals, stamens and foliage-leaves all come under the category leaf, though some are parts of the perianth, others are spore-bearing organs (sporophylls), and others carry on nutritive processes.
They are frequently provided with "pseudo-bulbs," large solid swellings of the stem, in the tissues of which water and nutritive materials are stored.
The quantity of digestible nutritive matter in 1000 lb of ordinary feeding-stuffs when supplied to sheep or oxen is shown in Table XIX.
F, Foot; op, operculum; mn, anal papilla; ry, dry, two portions of unabsorbed nutritive yolk on either side of the intestine.
Q, Sac containing nutritive mb, Mantle-skirt.
With regard to the nutritive value of oatmeal, as compared with that of wheat flour, it contains a higher percentage of albuminoids than any other grain, viz.
Its nutritive value, therefore, is higher than that of ordinary seconds flour.
The southern part of Alberta is covered by a short grass, very nutritive, but drying up in the middle of summer until the whole prairie is brown and unattractive.
Though frequently occurring, it is not a universal feature of plant life, and does not appear to be necessary or even directly connected with the nutritive system of plants.
Not only does exposure to heat sufficient to coagulate protein matter destroy life, by demolishing Life con- the molecular structure upon which life depends; but ditioned all vital activity, all phenomena of nutritive growth, by tern' movement and reproduction are possible only be- perature.
Waller (1816-1870), who tracked the line of nervous strands by experimental sections, and showed that when particular strands are cut off from their nutritive centres the consequent degeneration follows the line of the separated strands.
He speaks more favourably of the introduction of food into the stomach by a silver tube; and he strongly recommends the use of nutritive enemata.
It has been found by experiment that plants need for their nutritive process and their growth, certain chemical elements, namely, carbon, hydrogen, oxygen, nitrogen, sulphur, phosphorus, potassium, magnesium, calcium and iron.
The carbon compounds of the latter are of no direct nutritive value to the succeeding crop, but the decaying vegetable tissues very greatly assist in retaining moisture in light sandy soils, and in clay soils also have a beneficial effect in rendering them more open and allowing of better drainage of superfluous water and good circulation of fresh air within them.
On the degeneration of the polypide, its nutritive material is apparently absorbed for the benefit of the zooid, while the pig mented substances assume a spheroidal form, which either remains as an inert "brown body" in the body-cavity or is discharged to the exterior by the alimentary canal of the new polypide.
The embryo passes through three stages - (I) still enclosed within the egg and living on its own yolk; (2) free, within the vitelline mass, which is directly swallowed by the mouth; (3) there is no more vitelline mass, but the embryo is possessed of long external gills, which serve for an exchange of nutritive fluid through the maternal uterus, these gills functioning in the same way as the chorionic villi of the mammalian egg.
The chief danger with herbivorous and frugivorous creatures is that their constitutions are not adapted to the richness of cultivated fruits and cereals, and, in captivity, they may suffer mechanically from the want of bulk in their food supply, or if they eat a quantity sufficient in bulk, it contains an excess of nutritive material.
In short, there is the greatest difficulty in freeing milk on a large scale from germs without at the same time seriously prejudicing its flavour and nutritive value.
The paired ctenidia are very greatly developed right and left of the elongated body, and form the most prominent organ of the group. Their function is chiefly not respiratory but nutritive, since it is by the currents produced by their ciliated surface that food-particles are brought to the feebly-developed mouth and buccal cavity.
In an ascending scale, a plant is an organism with a nutritive soul; an animal is a higher organism with a nutritive, sensitive, orectic and locomotive soul; a man is the highest organism with a nutritive, sensitive, orectic, locomotive and rational soul.
It is frequently armed with spines, hooks or stylets, and is further complicated by the addition of a nutritive secretion (the prostate gland) which may open at its base or pass separately by a special duct to the exterior.