Chromatophores Sentence Examples
In all cases, while the internal threads which bear the cortical branches consist of elongated cells with few chromatophores, and no doubt serve mainly for conduction of food substances, the superficial cells of the branches themselves are packed with chromatophores and form the chief assimilating tissue of the plant.
In some cases both the nucleus and the chromatophores may be carried along in the rotating stream, but in others, such as T.Titeila, the chloroplasts may remain motionless iii a non-motile layer of the cytoplasm in direct contact with the cell wall.i Desmids, Diatoms and Oscillaria show creeping movements probably due to the secretion of slime by the cells; the swarmspores and plasmodium of the Myxomycetes exhibit amoehoid movements; and the motile spores of Fungi and Algae, the spermatozoids of mosses, ferns, &c., move by means of delicate prolongations, cilia or flagella cf the protoplast.
Chromatophores.The chromatophores or plastids are protoplasmic structures, denser than the cytoplasm, and easily distinguishable from it by their color or greater refractive power.
In young cells the chromatophores are small, colorless, highly refractive bodies, principally located around the nucleus.
Those chromatophores which remain colorless, and serve simply as starch-f ormers in parts of the plant not exposed to the light, are called leucoplasts or amyloplasts.
It is highly probable that starch is only produced as the result of the activity of chromatophores, either in connection with chromoplasts, chloroplasts or leucoplasts.
With reference to the existence of a chromatophore, he with others finds the colouring matter localized in granules in the peripheral region, but does not consider these individually or in the aggregate as chromatophores.
Algae are withdrawn from each of the three series enumerated above and consolidated into an entirely new group. In these algae, the colouring matter is said to be yellowish-green, not strictly green, and contained in numerous small discoid chromatophores which are devoid of pyrenoids.
The protoplast is uninucleate and vacuolate, and contains chromatophores of a brownish colour.
In Botrydium the chromatophores are small, without pyrenoids, and oil-drops are present; in Protosiphon the chromatophores form a net-work with pyrenoids, and the contents include starch.
AdvertisementIn certain Euphaeophyceae bodies built up of concentric layers, and attached to the chromatophores, were described by Schmitz as phaeophycean-starch; they do not, however, give the ordinary starch reaction.
It contains chromatophores in many species, coloured by a mixed lipochrome pigment which FIG.
In addition to diffuse pigment (mostly in the epidermis), the skin contains granular pigment stored up r' in cells, the chromatophores, restricted to the cutis, which are highly mobile and send out r2 branches which, by contraction and expansion, may rapidly alter the coloration, most batrachians being in this respect quite comparable to the famous chameleons.
Note the two rounded chromatophores in the top right hand side image.
Chlorophyll grains, chromatophores, starch-grains and oil-globuies, all of which can be distinguished either by their appearance or by chemical reagents, may also be present.
AdvertisementIn the chromatophores of many Algae and in the Liverwort Anthoceros there are present homogeneous, highly refractive, crystal-like bodies, called pyrenoids or starch-centres, which are composed of proteid substances and surrounded by an envelope of starch-grains.