Part 8 (1/2)

_Ascobolus_ (Fig 43) is a s some of this covered with a bell jar for a week or two, so as to retain the us will probably have43, _A_), of a light brownish color, and about as big as a pin-head

Its developest speci care to take up a little of the substratues are too small to be visible to the naked eye The spore fruits arise from filaments not unlike those of the mildews, and are preceded by the formation of an archicarp coh the walls of the young fruit (Fig 43, _B_) In the study of the early stages, a potash solution will be found useful in rendering the fruit has much the same structure as that of the mildews, but the spore sacs are much more numerous, and there are special sterile fila spore fruit is treated with chlor-iodide of zinc, it is rendered quite transparent, and the young spore sacs colored a beautiful blue, so that they are readily distinguishable

[Illustration: FIG 43--_A_, a s spore fruit, 300 _ar_ archicarp _C_, an older one, 150 _ar_ archicarp _sp_ young spore sacs _D_, section through a full-grown spore fruit (partly diagrammatic), 25 _sp_ spore sacs

_E_, development of spore sacs and spores: i-iii, 300; iv, 150

_F_, ripe spores _G_, a sterile filaus (_Peziza_), natural size]

The develop the young spore fruits in water The young spore sacs (Fig 43, _E_ i) are colorless, with granular protoplasm, in which a nucleus can often be easily seen The nucleus subsequently divides repeatedly, until there are eight nuclei, about which the protoplasm collects to form as many oval masses, each of which develops a wall and becos ii-iv) These are iranular, but afterwards becomes almost transparent As the spores ripen, the wall acquires a beautiful violet-purple color, changing later to a dark purple-brown, and43, _F_) The full-grown spore sacs (Fig 43, _E_, _W_) are oblong in shape, and attached by a short stalk The sterile filaed at the end (_G_) As the spore fruit ripens, it opens at the top, and spreads out so as to expose the spore sacs as they discharge their contents (Fig 43, _D_)

Of the larger cup fungi, those belonging to the genus _Peziza_ (Fig 43, _H_) are coround in woods They are soe-red, and very showy Another curious for in dry woods It is stalked like a mushroom, but the surface of the conical cap is honeycombed with shallow depressions, lined with the spore sacs

ORDER _Lichenes_

Under the na a good deal in structure, but i They are, with few exceptions, parasitic upon various forae, hich they are so intile plant They grow everywhere on exposed rocks, on the ground, trunks of trees, fences, etc, and are found prettythe co 44, _A_), growing everywhere on tree trunks, wooden fences, etc, forray, flattened expansions, with ins When dry, the plant is quite brittle, but onbecoreen in color The lower surface is white or brown, and often develops root-like processes by which it is fastened to the substratuments of the plant becorayish powder over certain portions of it

These, when supplied with sufficient moisture, will quickly produce new individuals

Not infrequently the spore fruits are to be met with flat discs of a reddish brown color, two or threea sus They are at first al 44, _A_, _ap_)

[Illustration: FIG 44--_A_, a common lichen (_Parmelia_), of the natural size _ap_ spore fruit _B_, section through one of the spore fruits, 5 _C_, section through the body of a gelatinous lichen (_Colleus filale _Nostoc_ thread _F_, spore sacs and paraphyses of _Usnea_, 300 _G_, _Protococcus_ cells and fungus filaments of _Usnea_]

If a thin vertical section of the plant is nified, it is found to be ular, thick-walled, colorless filai In the central parts of the plant these are rather loose, but toward the outside becoether, so as to for the filareen cells, that closer examination shows to be individuals of _Protococcus_, or soae, upon which the lichen is parasitic These are sufficiently abundant to forreen line just inside the rind if the section is exa 44, _B_)

The spore fruits of the lichens resei, and the spore sacs (Fig 44, _F_) are ht spores, which are sometimes two-celled The sterile filaments between the spore sacs usually have thickened ends, which are dark-colored, and give the color to the inner surface of the spore fruit

In Figure 45, _H_, is shown one of the so-called ”_Soredia_,”[7] a group of the algae, upon which the lichen is parasitic, surrounded by so spontaneously fro _sorediuhness of the filaments, the finer structure of the lichens is often difficult to study, and free use of caustic potash is necessary to soften and eable

[Illustration: FIG 45--For upon it, one-half natural size _B_, _Usnea_, natural size

_ap_ spore fruit _C_, _Sticta_, one-half natural size _D_, _Peltigera_, one-half natural size _ap_ spore fruit _E_, a single spore fruit, 2 _F_, _Cladonia_, natural size _G_, a piece of bark fro upon it, 2 _ap_ spore fruit _H_, _Sorediu to their form, lichens are sometimes divided into the bushy (fruticose), leafy (frondose), incrusting (crustaceous), and gelatinous Of the first, the long gray _Usnea_ (Fig 45, _A_, _B_), which drapes the branches of trees in swamps, is a fa 45, _C_) and _Peltigera_ (_D_) are types; of the third, _Graphis_ (_G_), common on the trunks of beech-trees, to which it closely adheres; and of the last, _Colleelatinous for like a colony of _Nostoc_, which indeed it is, but differing fro penetrated everywhere by the fila upon it

Not infrequently in this form, as well as in other lichens, special cavities, known as sper 44, _D_), are found, in which excessively small spores are produced, which have been claiations do not support this theory

[Illustration: FIG 46--Branch of a plum-tree attacked by black knot

Natural size]

The last group of the _Ascoi,”