The growth of the thallus proceeds by the regular segmentation of a single apical cell.
B) formed by certain lines of the superficial cells growing up from the surface, and as the thallus increases in area continuing to divide so as to roof in the chamber.
The large thallus of Conocephalus covers stones by the waterside, while Dumortiera is a hygrophyte confined to damp and shady situations.
Fungal hyphae occur in the rhizoids and in the cells of the lower region of the thallus of many liverworts, as in the endotrophic mycorhiza of higher plants.
In the moist state of the thallus these colours are much less apparent, as the textures then become more or less translucent, and the thallus usually prevents the greenish colour of the gonidia (e.
The fruticose thallus may be either erect, becoming pendulous, as in Usnea (fig.
B, Scytonema from the thallusof Stereocaulon famulosum.
In external form the heteromerous thallus presents the following modifications.
In about 100 species of lichens peculiar growths are developed in the interior of the thallus which cause a slight projection of the upper or lower surface.
An erect cylindrical thallus terminated by the fruit is termed a podetium, as in Cladonia (fig.
In colour also the thallus externally is very variable.
A, Optical longitudinal section of the extremity of a thin branch of the thallus which has become transparent in solution of potash.
A branched filiform thallus of Stigonema with the hyphae of the fungus growing through its gelatinous membranes.
When the fungus predominates in the thallus it has a bracket-like mode of growth and is found projecting from the branches of trees with the hymenium on the under side.
Cystococcus) from the thallus of Cladonia furcata.
It is possible that these Thallus plants have not arisen out of the Primaeval Algae, but out of one or more Monera, which, independently of the latter, arose by spontaneous generation.
This thallus is as yet not differentiated into axial-organs (stem and root) and leaf-organs.
In any case Mosses have arisen directly out of Thallus plants, and probably out of Green Algae.
Their lowest forms still possess, in both generations, a simple thallus like the Thallus plants; as for example, the Ricciae and Marchantiaceae.
Flowering plants cannot have directly arisen out of thallus plants, nor out of mosses; but only out of ferns, or Filicines.
Thallus without epidermis; capsule with a columella, short-pedicelled or sessile on the thallus.
Thallus small, depressed or sometimes cespitose, of lax texture; capsule often without sutures; spores dark brown, a half larger.
Thallus oblong with rounded lobes, distinctly areolate and porose, with imbricate sublunate scales beneath; gemmae in crescent-shaped receptacles.
Thallus wider (2'' or more), simple or irregularly lobed.
Capsule 2-valved, or dehiscing irregularly, or indehiscent; plant a thallus or thalloid stem.
Thallus fleshy, prostrate or assurgent from a creeping base; costa obscure.
Capsules immersed in the thallus or sessile upon it, indehiscent.
The thallus is of more varied structure in this group than in any other.
The sexual organs--oogonia and antheridia---are borne on special portions of the thallus in cavities known as conceptacles.
In the whole series of the Confervales, the thallus consists of filaments branched or unbranched, attached at one extremity, and growing almost wholly at the free end.
The Ulvaceae, the thallus of which consists of laminae, one or more cells thick, or hollow tubes, probably represent a still more advanced stage in the passaae of a colony into a multicellelar plant.
Indeed the genus Oedogonium exhibits a high degree of specialization in its reproductive system, considering that its thallus has not advanced beyond the stage of an unbranched filament.
Valoniaceae and Dasycladaceae are partially septate, but elsewhere no cellulose partitions occur, and the thallus is more or less the continuous tube from which the group is named.
The ventral portion of the carpogonium may be imbedded deep in the thallus in the massive species; the trichogyne, however, always reaches the surface.
In unicellular forms (Sphaerella) the thallus becomes transformed into a zoosporangium at the reproductive stage.
In all Conjugatae and most Protococcales, and in the bulk of the Confervales, the thallus consists of a cell or cells, the Protoplast of which contains a single nucleus.
The thallus is somewhat spherical and unicellular, exhibiting a distinction between anterior and posterior extremities, and dorsal and ventral surfaces.
In Fucaceae an apical cell is situate at the surface of the thallus in a slit-like depression at the apex.
In Fucus vesiculosus they arise in lateral pairs; in Ascophyllum they are single and median; in Macrocystis one vesicle arises at the base of each thallus segment; in Sargassum and Halidrys the vesicles arise on special branches.
He finds that eight chromosomes appear in karyokinesis in the ordinary thallus cells, but sixteen in the gonimoblast filaments derived from the fertilized carpogonium.
Attached to the bottom of pools by means of rhizoids, the thallus of Characeae grows upwards by means of an apical cell, giving off whorled appendages at regular intervals.
The specimens gathered ought in every case to be of sufficient size to show distinctly the character of the thallus and of the fructification.
By cutting across the thallus of the above species, we can perceive even by the naked eye that it consists of three different layers, which when microscopically examined present the appearance shown in the above figure.
Suffice it at present to say that sections must be made of the thallus to ascertain the character of its different layers, as also sections of the apothecia and spermagones to ascertain the nature of the spores and spermatia.
Piece of thallus of Parmelia conspersa, with section through an apothecium.
Piece ofthallus of a Sticta, with section, showing the immersed apothecia; the small openings of these dot the surface.
Alga-like fungi with unicellular thallus and well-marked sexual organs.
Thallus septate; spores developed in special type of sporangium, the ascus, the number of spores being usually eight.
It attaches itself to rocks, pebbles and boulders by means of a basal disk which serves merely as a mechanical support, the frond or thallus absorbing its nourishment from the sea water.
Thallus closely attached to the substratum at the center, the lobes ascending, 6 to 8 cm.
Cortex developed on the upper side of thallus only, spores hyaline Peltigera.
A section through the thallusof Nephroma helvetica, showing the cortices, upper and lower, and the mycelial medulla within.
Like other algae, the melanospores grow by a continued process of cell-division, and when portions of the thallus are worn away during stormy weather, they are renewed by the same process.
In some cases the fragments of a thallus that have been detached by storms or other mechanical means possess the power of independent growth, and develop into plants; and this mode of reproduction may often be watched in the indoor aquarium.
The thallus or plant-body is very varied in form, sometimes consisting of a broad membrane, but more commonly of tufts of slender green filaments or of narrow, flattened fronds.
Near the margins of the lobes of the thallus are small dark points.
The structure of thethallus may serve to represent that of most of the Lichens.
The thallusof these Lichens forms little rounded irregularly overlapping scales, with scalloped edges, overgrowing the surface upon which the Lichens are found.
On the upper surface of the thallus of Parmelia (fig.
The thallus does not yet show this important morphological division.
On the other hand, they are wanting in the lower liverworts, which form a thallus like many of the algae; thus, for instance, the liverwort riccia fluitans is just like the brown alga dictyota dichotoma.
He may claim to be the greatest of magicians in whose presence Thallus has remained for any considerable time upon his feet.
Deny then, if you dare, that Thallus used to have fits of epilepsy long before I came to Oea, or that has frequently been shown to doctors.
Thallus only is absent owing to the fact that he has been banished to a place some hundred miles distant.
Even you will not deny that Thallus was epileptic.
The literal meaning is 'Thallus contracts his hands, you collect advocates'.
I ask you, Maximus, to question these fourteen slaves whom we have produced as to where the boy Thallus is and what is the state of his health; I ask you to question my accuser's slaves.
I have good reason for asking you to name those who witnessed that guilty ritual when I cast the moribund Thallus into one of his fits.
They are set free by the rupture of the ascus, and germinate by putting out through their walls one or more filaments which branch and form the thallus of a new individual.
In these there is a thallus which starts from a central point and continually divides in a forked or dichotomous manner.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "thallus" in a variety of sentences. We hope that you will now be able to make sentences using this word.
