Mycelium

“ The delicate threads of the mycelium are formed of rows of cells placed end to end, and microscopic inspection of thin slices from the stem and cap show, that they also are composed of cells alone.
The rank of this plant in the vegetal kingdom is settled by the direction of growth of its vegetative system and by the nature of its tissues. All flowering plants, as well as the ferns and mosses, have their vegetative part made up of root, stem, and leaves. The root grows downward and the stem upward. But the growth of the mycelium, the vegetative system of the mushroom, is horizontal ”

“ Every plant of which this mycelium forms a part, spreading its web throughout the substance on, or in, which it grows, belongs among fungi. Most of the species are either quite invisible, or else their parts are so small as to be indistinguishable. But some sort of reproductive organs exist, and spores are always produced. The mycelium is often so minute as to traverse living plants and the pores of solid wood. It grows rapidly and causes quick decay. ”

“ The removal of mycelium and resting spores from the seed chosen, to be accomplished by drying in the sunlight, and by dipping the seed-potatoes in a solution of lime with a little carbolic acid; and 3. The preservation of seed in a temperature which will prevent the growth of mycelium. It will not grow in a temperature below 48° Fahr. ”

“ Sometimes mycelium unites in bundles more or less thick and branched. This has been called the fibrous mycelium. Where the filaments intercross closely, are felted, and inclined to form a membrane, it is hymenoid mycelium. Where the filaments are so small and close that they form very compact bodies, constituting those solid irregular products called sclerotium, it is scleroid or tuberculous mycelium. With malacoid mycelium we have nothing to do in this paper. It is a soft, pulpy, fleshy mycelium.
Systematists have divided the Agaricini into groups according to the color of their spores. ”

“ On the mycelium soon appear, besides those which are spread over the tissue of the leaves, strong, thick, mostly fasciculate branches, which stand close to one another, breaking forth from the leaf and rising up perpendicularly, the conidia-bearers. They grow about 1 mm. long, divide themselves, by successively rising partitions, into some prominent cylindrical linked cells, and then their growth is ended, and the upper cell produces near its point three to six branches almost standing rectangularly. ”

“ Mostly, simple plants are too small to be individually [22] visible without the microscope. But, in some cases, these vegetal aggregates of the first order grow to appreciable sizes. In the mycelium of some fungi, we have single cells developed into long branched filaments, or ramified tubules, that are of considerable lengths. An analogous structure characterizes certain tribes of Algæ, of which Codium adhærens, Fig. ”

“ From the pseudomycelium arise true hyphæ (b) , each of which in turn ends in a chain of spores (c) . [Pg 129]
MORPHOLOGY OF THE BLASTOMYCETES.
The blastomycetes are composed of spherical or oval cells (8 to 9.5μ in diameter) , which, when rapidly multiplying by budding, may form a spurious mycelium. A thin cell-wall encloses the granular protoplasm, in which vacuoles and sometimes a nucleus may be noted. This latter is best seen when stained with hæmatoxylin (see page 105) .
During their growth and multiplication the blastomycetes split up solutions containing sugar into alcohol and CO2. ”

“ The threads (or the hyphæ) clog the air-spaces of the leaf and often plug the stomates, and they also appropriate and disorganize the cell fluids; thus they injure or kill their host. The mass of hyphæ of a fungus is called mycelium. Some of the hyphæ finally grow out of the leaf and produce spores or reproductive cells that answer the purpose of seeds in distributing the plant (b, Fig. 132) .
A plant that lives on dead or decaying matter is a saprophyte. Mushrooms (Fig. 131) are examples; they live on the decaying matter in the soil. Mould on bread and cheese is an [108] example. ”

“ Filamen ́tous-Myce ́lium, Floc ́cose-Myce ́lium, mycelium of free hyphæ which are at most loosely interwoven, but without forming bodies of definite shape and outline.
Fil ́aceous, Fil ́iform (filum, a thread, + aceous) , like a thread or filament.
Fim ́briate, Fim ́briated (fimbriatus, < fimbriæ, a fringe) , fringed; cut jaggedly.
Fis ́sile (fissilis, cleft, < fissus, pp. findere, split) , capable of being split, cleft or divided in layers. ”

“ Such spherical expansions in a mycelium, either terminal or intercalary, may be sporangia, oogonia or large resting-spores, or non-fungal cell-contents, and it is usually impossible in the absence of the contents to determine their precise nature. Hartig [417] and others have drawn attention to the occurrence of such bladder-like swellings in the mycelia of recent fungi, which have nothing to do with reproductive purposes; under certain conditions the hyphae of a fungus growing in the cavity of a cell or trachea may form such vesicles, and these, as in fig. ”

“ Now, nature might have made one kind of cell and magic jelly for the fungi, and another kind for green plants, but she didn't. She seems to like to see how many different things she can make of a few simple things. All the plants and animals begin to grow in a little cell of protoplasm. So, when we understand the fungi, the simplest of all plants, we have learned the A. B. C.'s of life. Knowing the letters, we can spell the words and read the story of the living world. (See Fungi, Yeast, Mould, Mildew, Rust, Smut, Mushrooms, Toadstools, etc.) ”

“ I have put some under each microscope, and those who can look into them will see the slide almost covered with small round green cells very much like the yeast cells we saw when studying the Fungi, only that instead of being colourless they are a bright green. Some of these cells will I suspect be longer than others, and these long cells will be moving over the slide very rapidly, swimming hither and thither, and you will see, perhaps for the first time, that very low plants can swim about in water. ”

“ They are colorless, or light yellowish, regularly disposed; but their function is not known. Besides these, certain cells become thick-walled, and form resting cells (spores) for the propagation of the plant (Fig. 7, C. sp.) . In species where the sheath of the filament is well marked (Fig. 7, H) , groups of cells slip out of the sheath, and develop a new one, thus giving rise to a new plant.
The bacteria (Schizomycetes) , although among the commonest of organisms, owing to their excessive minuteness, are difficult to study, especially for the beginner. ”

“ Classification.—It has been accepted for some time now that the majority of the fungi proper fall into three main groups, the Phycomycetes, Ascomycetes and Basidiomycetes, the Schizomycetes and Myxomycetes (Mycetozoa) being considered as independent groups not coming under the true fungi. ”

“ But besides this means of increase I assume that cells, before their conversion into completely passive or "formed material," throw off minute granules or atoms, which circulate freely throughout the system, and when supplied with proper nutriment multiply by self-division, subsequently becoming developed into cells like those from which they were derived. These granules for the sake of distinctness may be called cell-gemmules, or, as the cellular theory is not fully established, simply gemmules. ”

“ But the blindness of those who think it absurd to suppose that complex organic forms may have arisen by successive modifications out of simple ones, becomes astonishing when we remember that complex organic forms are daily being thus produced. A tree differs from a seed immeasurably in every respect—in bulk, in structure, in colour, in form, in chemical composition: differs so greatly that no visible resemblance of any kind can be pointed out between them. Yet is the one changed in the course of a few years into the other: ”

“ Though I do not believe that a plant will spring up where no seed has been, I have great faith in a seed—a, to me, equally mysterious origin for it. Convince me that you have a seed there, and I am prepared to expect wonders. ”

“ IF we would hear the children of the sun, we must shut the door of our prosaic room behind us, and hurry out before the coming on of dusk to the pond, into the green field, on the moor, to the edge of the wood where life in the double form of animal and plant unfolds itself without restraint. From up in the air, from plants, flowers, grass, holes in the ground, and the moisture of puddles, come a chirping and rattling, a humming and buzzing, a piping and singing of the host of winged and wingless creeping and hopping insects. ”

“ Diagram of the same cell of a tentacle, showing the various forms successively assumed by the aggregated masses of protoplasm. ”

“ But first I was to prepare more land, for I had now seed enough to sow above an acre of ground. Before I did this, I had a week’s work at least to make me a spade, which, when it was done, was a very sorry one indeed, and very heavy, and required double labour to work with it; however, I went through that, and sowed my seeds in two large flat pieces of ground, as near my house as I could find them to my mind, and fenced them in with a good hedge, the stakes of which were all cut off that wood which I had set before, which I knew would grow; ”

“ The Microbe is so very small
You cannot make him out at all,
But many sanguine people hope
To see him through a microscope. ”

“ 29 And God said, Behold, I have given you every herb bearing seed, which is upon the face of all the earth, and every tree, in the which is the fruit of a tree yielding seed; to you it shall be for meat. 30 And to every beast of the earth, and to every fowl of the air, and to every thing that creepeth upon the earth, wherein there is life, I have given every green herb for meat: and it was so. ”

“ The gnats dance in joyous swarms which the slightest breath of wind disperses like a column of smoke; butterflies and moths, in wedding-garments, their wings powdered with silvery dust and their antennæ spread out like plumes, join in the frolic or seek places in which to deposit their eggs; the wood-borer comes forth from its hidden retreat under the bark of the elm; the weevil breaks its cell hollowed out in a grain of wheat; the plume-moths rise in clouds from the granaries and fly toward the fields of ripe cereals ”

“ The planted seed consigned to common earth,
Disdains to moulder with the baser clay;
But rises up to meet the light of day,
Spreads all its leaves, and flowers, and tendrils forth;
And, bathed and ripened in the genial ray,
Pours out its perfume on the wandering gales,
Till in that fragrant breath its life exhales. ”

“ In this broad earth of ours, Amid the measureless grossness and the slag, Enclosed and safe within its central heart, Nestles the seed perfection. ”

“ Look at a plant in the midst of its range! Why does it not double or quadruple its numbers? We know that it can perfectly well withstand a little more heat or cold, dampness or dryness, for elsewhere it ranges into slightly hotter or colder, damper or drier districts. In this case we can clearly see that if we wish in imagination to give the plant the power of increasing in numbers, we should have to give it some advantage over its competitors, or over the animals which prey on it. ”

“ For an Apple is in itself a little Universe; the Seed, hotter than the other parts thereof, is its Sun, which diffuses about it self that natural Heat which preserves its Globe: And in the Onion, the Germ is the little Sun of that little World, which vivifies and nourishes the vegetative Salt of that little mass. ”

“ The bud disappears when the blossom breaks through, and we might say that the former is refuted by the latter; in the same way when the fruit comes, the blossom may be explained to be a false form of the plant's existence, for the fruit appears as its true nature in place of the blossom. These stages are not merely differentiated; they supplant one another as being incompatible with one another. ”

“ In the span of my own lifetime I have observed such wondrous progress in plant evolution that I look forward optimistically to a healthy, happy world as soon as its children are taught the principles of simple and rational living. ”

“ Perhaps the immense Milky Way which on clear nights we behold stretching across the heavens, this vast encircling ring in which our planetary system is itself but a molecule, is in its turn but a cell in the Universe, in the Body of God. All the cells of our body combine and co-operate in maintaining and kindling by their activity our consciousness, our soul; ”

“ A sensitive plant in a garden grew,
And the young winds fed it with silver dew,
And it opened its fan-like leaves to the light,
And closed them beneath the kisses of night. ”

“ there can surely be no difficulty in understanding how, under appropriate conditions, a cell may, in the course of untold millions of years, give origin to the human race. ”

“ After commenting on these purely imaginary causes, I pointed out in 1832, as the two great flaws in Lamarck's attempt to explain the origin of species, first, that he had failed to adduce a single instance of the initiation of a new organ in any species of animal or plant; and secondly, that variation, whether taking place in the course of nature or assisted artificially by the breeder and horticulturist, had never yet gone so far as to produce two races sufficiently remote from each other in physiological constitution as to be sterile when intermarried, or, if fertile, only capable of producing sterile hybrids, &c. ”