HARDWICKE'S SCIENCE-GOSSIP. 



227 



nearly evaporated, I moistened the outside of the 

 earth opposite the bottom of the cell, and the mother 

 perceiving this, actually dug a gallery right through 

 to the spot where she found the best supply of mois- 

 ture. Having neglected to moisten the earth for 

 some days, it again became dry, and there was none 

 [sic, i.e. no moisture], even round the rim of the 

 glass as before. Under those circumstances, the 

 mother earwig found a little remaining moisture 

 quite under the clod of earth ; upon the board of the 

 mantel-piece, and thither she forthwith carried her 

 eggs. The subsequent proceedings were not less 

 interesting ; for though I carefully moistened the 

 earth every day, she regularly changed the situation 

 of the eggs morning and evening, placing them in 

 the original cell at night, and on the board under the 

 clod during the day, as if she understood the evapora- 

 tion to be so great when the sun was up, that her 

 eggs might be left dry before night. I regret to add 

 that during my absence the glass had been removed 

 and the mother escaped, having carried away all her 

 eggs but one or two, which soon shrivelled up." 

 Milford, Letter keimy. 



A GOSSIP ABOUT FUNGI. 

 By George Massee. 



A DEFINITION of a fungus will probably, and not 

 unreasonably, be expected, on the first page ; 

 nevertheless, such definition is undoubtedly the most 

 difficult part of the work we have undertaken to pro- 

 duce. The numerous orders and genera, whose defini- 

 tions extend over a score or more octavo pages, and 

 which are all derived from the variability, presence, 

 or absence of some of the essential features that con- 

 stitute a fungus, prove the impossibility of expressing 

 clearly, within a reasonable space, the elasticity of 

 fungal life. Certain characters, structural and phy- 

 siological, are met with in the organisms constituting 

 the vegetable kingdom, and it is the varied association 

 of certain of these characters in different individuals 

 that give us the divisions known as Orders, Families, 

 Genera, &c. The great difficulty in attempting 

 classification does not consist in arranging into groups 

 all plants possessing so many features in common, 

 but in determining at what stage a character is suffi- 

 ciently developed or arrested, to entitle the organism 

 exhibiting the change to occupy a place in a precon- 

 ceived arrangement. " Natura non facit saltus." 

 Structural changes which may be looked upon as the 

 manifestation of physiological changes, themselves 

 again dependent on the stability of surroundings, are 

 introduced step by step, and disappear in a similar 

 manner, may be compared to a spindle-shaped body ; 

 and every group of plants, nay, every species, is com- 

 posed of more or less of these spindles, a few entire, 

 or nearly so, constituting its so-called characteristics, 



and portions of others, the mass of which forms one 

 of the characters of allied groups or species, allied, 

 but not the same, because what is appearing or dis- 

 appearing in the one, is yet a prominent feature in 

 the other. 



In fungi there is an entire absence of chlorophyll, 

 hence they are unable to assimilate inorganic food, 

 and require for their support organic substances ; 

 consequently they are either saprophytes, growing on 

 decaying animal or vegetable matter, or parasites, 

 when developed, on living plants or animals. The 

 larger terrestrial fungi appear to offer an exception to 

 the above statement, but a closer examination shows 

 that they are attached to leaves, roots of plants, or 

 the soil contains a large amount of organic matter. 



Apart from furnishing food and shelter to myriads 

 of beetles and allied insects, fungi may be looked 

 upon as Nature's vegetable scavengers ; so long as an 

 animal or plant is vigorous, it more than compensates 

 for food and space occupied, but the instant it begins 

 to languish, Nature manifestly says the sooner it is 

 out of the way the better ; fungi innumerable, large 

 and small, prey upon it, attain their full development 

 at its expense, and then disappear as if by magic. 

 Thus an enormous amount of material, which but for 

 fungi would remain for a long time in a passive state, 

 is speedily converted into suitable food for other 

 plants. 



Fungi are broken up into two primary groups, 

 depending on the mode of origin of the germinating 

 bodies. 



I. Sporifera. — Spores naked, not during any 

 period contained in special sacs or cells. In the 

 higher fungi, as the edible mushroom, the spores 

 originate from cells called basidia ; each basidium is 

 surmounted by four thin spicules or sterigmata, and 

 each sterigma bears at its lip a spore. The term 

 spore is restricted to such reproductive cells as origi- 

 nate in the above-mentioned manner. Spores pro- 

 duced on basidia are sometimes called basidiospores. 

 (Fig. 134, a. b.) 



II. Sporidiifera. — Germ cells produced in 

 special cells or sacs, and called sporidia. There are 

 two types : a, when the contents of a certain cell break 

 up into an indefinite number of sporidia, the contain- 

 ing cells are usually more or less spherical, and are 

 called sporangia (fig. 135). An example is to be found 

 in the mould (Mucor viucedo), common on jam, &c, 

 looking like little black or gold headed pins ; b, when 

 the sporidia are produced in definite number, gener- 

 ally eight in a lengthened cell called an ascus 

 (fig. 136), or theca, such sporidia are sometimes 

 spoken of as thecaspores or aseospores. The small 

 cup or saucer shaped fungi, to be met with on rotten 

 sticks and stumps, are examples. 



The spores are invariably microscopic, yet the 

 variety both in form and colour is endless ; from a 

 perfect sphere, there is every transition to the linear 

 sporidium as long as the ascus. In some instances, 



