Rhodium

“ Rhodothamnus, rō-dō-tham′nus, n. a genus of small shrubs, the ground Cistus. [Gr. rhodon, rose, thamnos, bush.]
Rhodymenia, rō-di-mē′ni-a, n. a genus of marine algæ. [Gr. rhodon, rose, hymēn, membrane.]
Rhœadic, rē-ad′ik, adj. pertaining, to or derived from, the red poppy, Papaver Rhœas.—n. Rhœ′adine, a non-poisonous alkaloid found in the same. [Gr. rhoias, rhoiados, a poppy.]
Rhomb, romb, n. a quadrilateral figure having its sides equal but its angles not right angles: (crystal.) a rhombohedron: (Milt.) a material circle—also Rhom′bus.—adj. Rhom′bic.—ns. ”

“ Rhodora canadensis is a little American shrub128 with pink flowers, which appear before the leaves, and the corolla of which is bilabiate, the upper lip being the broadest, and cut into two or three teeth, and the lower only once cut. There are ten stamens, and the capsule is five-celled and five-valved. The leaves are deciduous, and slightly pubescent beneath; and the flowers are produced in small terminal clusters. This plant, as well as all the Azaleas above described, are now included by some botanists in the genus Rhododendron. ”

“ Cells of the thallus contain a red colouring matter in addition to the green chlorophyll. The reproduction is asexual and sexual; the formation of asexual reproductive cells (tetraspores) in groups of four in sporangia is a characteristic method of reproduction. Sexual reproduction is effected by means of distinct male and female cells.
With the exception of a few fresh-water genera all the red algae are marine. The Rhodophyceae, like the Cyanophyceae and Chlorophyceae, include a shell-boring form which has been found in the common razor-shell [343] . ”

“ The rich and brilliant Rhodymenia laciniata is not uncommon, and the more delicate and scarcely less beautiful Nitophyllum punctatum (See Plate V.) , with Delesseria sanguinea and sinuosa, and many other species equally attractive, occur. Some of these are it is true deep-water kinds, washed in by the tides; the first named, for example, I have never met with in a growing state; but this little bay is particularly rich in littoral species. At the bottom of the wall or quay-like edge, grow several fine tufts of those very elegant Algæ, Griffithsia corallina, and G. setacea ”

“ At the periphery of the lobes are some comparatively thin-walled living cells mixed with a few thin-walled hydroids, the remains of the thin-walled hydrom mantle of the aerial stem. Outside this are three arcs of large cells showing characters typical of the endodermis in a vascular plant; these are interrupted by strands of narrow, elongated, thick-walled cells, which send branches into the little brown scales borne by the rhizome. The surface layer of the rhizome bears rhizoids, and its whole structure strikingly resembles that of the typical root of a vascular plant. ”

“ Fig. 12 is a highly interesting variety of the primitive crystal, as it forms the passage of it, as fig. 13 will shew, into the acute rhomboid, fig. 15, of which fig. 14 is the intermediary stage. This rhomboid, I have not, from the minuteness of the crystals, which, though numerous, exceed not in size the extremity of the smallest pin, been able to submit to the goniometer. This form also exists in the Spinelle ruby and in the diamond; which, as well as the red oxyd of copper, have for their primitive form, the regular octahedron, and give an acute rhomboid of 60 and 120d. ”

“ The phæodium, or the peculiar dark extracapsular pigment-body of the Phæodaria, is one of the most important and most characteristic parts of their organisation, and has induced me to derive their name from it; it is not less typical for the whole legion, than the astropyle with its radiate operculum and the proboscis; and both these important parts are always in direct topographical and physiological connection. Whilst I have missed the phæodium in no Phæodarium in which the soft body was well preserved, I have not found it in any other Radiolaria ”

“ Rhodophane, rō′dō-fān, n. a red pigment found in the retinal cones of the eyes of certain fishes, reptiles, and birds. [Gr. rhodon, rose, phanēs, appearing.]
Rhodophyl, rō′dō-fil, n. the compound pigment found in the red algæ.—adj. Rhodophyl′lous. [Gr. rhodon, rose, phyllon, leaf.]
Rhodopsin, rō-dop′sin, n. a purple pigment found in the retina. [Gr. rhodon, rose, opsis, view.]
Rhodora, rō-dō′ra, n. a handsome shrub with terminal clusters of pale purple flowers preceding the deciduous leaves: a genus of Ericaceæ, now included in Rhododendron. [Gr. rhodon, a rose.] ”

“ He wondered for what ordeal the neophyte was prepared in this singular apartment. He wondered how such neophytes were chosen, and to what tests they were submitted before being accepted as members of the bloodthirsty order. He could not even surmise.
Evidently no neophyte had been accepted on the previous night, unless there were other like chambers in the house. The occupants of the shuttered cars must therefore have been more advanced members. ”

“ The rotational streaming in plant cells, such as those of Chara, is very similar to the rotational streaming in paramecium and numerous other ciliates. In these organisms it is often called cyclosis. A paramecium differs, however, from a plant cell exhibiting rotational streaming in that no central vacuole is present. This space in paramecium is occupied by the gullet, the nucleus and some endoplasm which is not in the main stream. ”

“ Most of the larger species of marine Rhodophyceae are attached by means of a disc to rocks, stones or shells. Many are epiphytic on other algae, more especially the larger Phaeophyceae and Rhodophyceae. As in the case of epiphytic brown seaweeds, the rhizoids of the epiphyte often penetrate the substance of the supporting alga. Some Red Algae find a home in the gelatinous substance of Flustra, Alcyonidium and other polyzoa, only emerging for the formation of the reproductive organs. ”

“ During its second year from seed one basal leaf is sent up, followed in the third year by another smaller leaf and the flower.
Description of the Rhizome, or Rootstock.
The rhizome (rootstock) and rootlets of Golden Seal, or hydrastis, as it is also known in the drug trade, are the parts employed in medicine. The full-grown rhizome, when fresh, is of a bright yellow color, both internally and externally, about 1 1/2 to 2 1/2 inches in length, and from one-fourth to three-fourths of an inch in thickness. ”

“ To the extreme left, under the beautiful Rhodymenia, is a small branch of the bright, olive-tinted Ectocarpus tomentosus, looking much like a spray of wild Broom, and immediately below it, a few purple branchlets of Gracilaria confervoides; while in the left foreground lies a pebble, partly covered by a small plant of Zonaria parvula, from beneath which straggles a little branch of the common but pretty Coralline, the Corallina officinalis; and, to the right, a globe of the curious Codium bursa, of the French coast, which might easily be added to our native species in the Aquarium. ”

“ The rhododendrons were then in full flower, and the hills were one blaze of colour. We were always going up and up, and as we ascended, the deep crimson rhododendron flowers of Naini Tal gradually faded to rose-colour, from rose-colour to pale pink, and from pink to pure white. It was a perfect education travelling with Colonel Erskine, for that shrewd and kindly old Scotsman had spent half his life in India, and knew the Oriental inside out. ”

“ Frustule in zone view linear, linear-elliptical (in our species) , or clavate. Valve reniform or lunate; a raphe, not visible in some species in the usual position of the valve, is found along the convex edge or keel. Median and terminal nodules, although very small, can be determined. The name is more appropriate to the African species which are clavate. Two species only are found in this locality.
The chief distinction between Epithemia and Rhopalodia is in the position of the raphe and the nodules. ”

“ These are for the most part long, thin-walled, unicellular and colourless, and arise from the outer cells of the pseudo-cortex, or from the terminal cells of branches when the filaments are free. Among Rhodomelaceae, hair-like structures of a higher order are known. These arise from the axial cell, and are multicellular and branched. They soon fall off, and it is from the persistent basal cell that the branches of unlimited growth arise. ”

“ This attracts sufficient moisture to burst open the outer, and then it begins to increase by the subdivision of its cells, until the primary green prothallus D is formed. This falls to the ground, and, being furnished on its under side with thread-like fibres, fixes itself to the earth, and thus is developed the rhizome, or root of the future plant. In each of the antheridia, which are numerous, a cell is formed, chiefly filled with albuminous matter and free spores, each having attached a flat ribbon-like filament, or stermatoid, curled in a spiral manner. ”

“ In order to compare the minute structure of the rostellum and stigma, I examined young flower-buds of Epidendrum cochleatum and floribundum, which, when mature, have a simple rostellum. The posterior parts of both organs were quite similar. The whole of the rostellum at this early age consisted of a mass of nearly orbicular cells, containing spheres of brown matter, which resolve themselves into the viscid fluid. The stigma was covered with a thinner layer of similar cells, and beneath them were the coherent spindle-formed utriculi. ”

“ There are two distinct varieties of scenery with both of which rhododendrons consort magnificently. One is heavy, boggy ground, deep, dark, and oozy, under large trees, into the recesses of which they can settle, spreading out in all directions, re-rooting themselves as they choose in the black earth; their flowers catching the divided sunrays, and turning every hollow place into a pool of colour. Another, and a yet more ideal place is a steep hillside, provided that it is furnished with boulders, and provided that the said boulders are not of limestone. ”

“ Every individual cell, now inhabited by its tentacled Hydra, has in its turn budded out from a branch, which was itself but a lateral process from the central axis. And this was but the prolongation of what was at first a single cell, shooting up from a creeping root-thread. A little earlier than this, there was neither cell nor root-thread, but the organism [Pg 120] existed in the form of a planule, a minute soft-bodied, pear-shaped worm, covered with cilia, that crawled slowly over the stones and sea-weeds. ”

“ Uses—A decoction of the seeds (1 p. to 70 p. of water) is employed in India as a cooling, demulcent drink. The seeds powdered and mixed with sugar, or made gelatinous with water, are sometimes given in chronic diarrhœa.
POLYGONACEÆ. RADIX RHEI. Rhubarb; F. Rhubarbe; G. Rhabarber.
Botanical Origin—No competent observer, as far as we know, has ever ascertained as an eye-witness the species of Rheum which affords the commercial rhubarb. Rheum officinale, from which it seems, at least partly, derived is the only species yielding a rootstock which agrees with the drug. ”

“ The term “colony” is, perhaps, inappropriate, as the whole mass of cells arises from a single one, and may properly be looked upon as an individual plant.
[3] Algæ (sing. alga) .
[4] “Host,” the plant or animal upon which a parasite lives.
[5] The antheridia, when present, arise as branches just below the oögonium, and become closely applied to it, sometimes sending tubes through its wall, but there has been no satisfactory demonstration of an actual transfer of the contents of the antheridium to the egg cell. ”

“ The whole seed of some plants is so small that it can be lifted bodily by the wind, for instance Rhododendrons and many other heaths, one of the hanging pitcher plants of tropical Asia, many orchid seeds, and of hundreds of other plants. Many of these are less than one ten-thousandth of a gram in weight and, with dust and the spores of nearly all cryptogams, may be transported thousands of miles. ”

“ The suggestion that they are mere excretions, or half-digested matters, as Hertwig supposes ("halb assimilirte Nahrungs-bestandtheile," 1879, loc. cit., p. 99) seems less probable. The most important fact illustrating their high signification for the processes of nutrition, digestion and for effecting changes on matter, seems to be the close relation of the phæodium to the astropyle; the radiate operculum of the latter, and the proboscis arising from it, being constantly covered and completely hidden by the central main mass of the phæodium. ”

“ The carpels are free and are placed opposite the petals (Fig. 487) . Fruit a syncarp composed of follicles containing [452] many, small seeds without endosperm. Outside each carpel is found a small, nectariferous scale (Fig. 487) . The northern genus, Rhodiola, is diœcious. The petal-stamens are wanting in some (Crassula, Bulliarda, and others) . The floral-leaves are very often displaced upon their axillary branches. A multicarpellary gynœceum also occurs. ”

“ The genus Lithogromia and the two following genera represent together the subfamily Lithogromida, comprising those Challengerida in which the mouth of the shell is a simple opening, and not prolonged into a pharynx or an internal prominent tube. Lithogromia may be regarded as the common ancestral form of this family, since it is the simplest of all, and possesses no external apophyses, neither teeth on the mouth, nor spines on the margin of the smooth shell. ”

“ The Nucleus always lies centrally in the Spumellaria monozoa and is serotinous, for it divides only at a later period into the nuclei of the spores; in the Spumellaria polyzoa it is precocious, and divides early into many small nuclei. (3) The Pseudopodia are exceedingly numerous and distributed evenly over the whole surface of the central capsule. (4) The Calymma contains no phæodium. (5) The Skeleton is seldom wanting, is never centrogenous, and is always siliceous. (6) The Ground-form of the central capsule is originally spherical (often modified) ”