ASCO] 



€§z Ereagurg al Uotaitg. 



100 



shooting out its asci when mature. The 

 species grow almost exclusively on the 

 dung of various animals. One, however, 

 is found on decayed leather ; and another, 

 whicii is perhaps a doubtful species, occurs 

 on clover leaves. The sporidia are often 

 of a beautiful colour and form exquisite 

 objects under the microscope. Few Fungi 

 are more common than Ascdbolns furfnra- 

 cens, on old cow-dung. [M. J. B.] 



ASCOMYCES. A small genus of Fungi 

 of the most simple construction, remark- 

 able principally for the effect they have 

 upon the plants upon which they are de- 

 veloped. The whole plant consists of a 

 stratum of club-shaped cells filled with 

 sporidia, with scarcely any filamentous or 

 cellular base developed in the shape of a 

 white powder on the surface of the leaves, 

 which are generally swollen and distorted, 

 as is especially in the case with blistered 

 peach-leaves, when attacked by Ascomyces 

 deformans. The asci are either accompani ed 

 by naked spores which sprout like the cells 

 of yeast, or else the sporidia, when set free, 

 are propagated after the same fashion. 

 The genus occurs on the leaves of trees, 

 or sometimes of herbaceous plants, as 

 Trientalis europcea. The most obvious 

 examples besides those mentioned above 

 are the Ascomyces of the walnut and pear, 

 which trees are, however, far less de- 

 formed by it than the peach. [M. J. B.] 



ASCOMYCETES. A large division of 

 Fungi distinguished by their fruit being 

 contained in hyaline sacs (asci), and not 

 situated at the top of certain privileged 

 cells as in the mushrooms and allied Fungi. 

 The asci are placed parallel to each other, 

 barren threads or sacs intervening, and 

 are packed into a thin stratum, which 

 equally with the fructifying stratum of 

 mushrooms is called the hymenium. This 

 may be entirely exposed, or may be in eluded 

 in an especial organ called a perithecium. 

 The asci are for the most part colourless, 

 and vary from mere threads to globose 

 sacs. The sporidia or fructifying bodies 

 which they contain are generally definite 

 in number and multiples of two. Their 

 most usual number is eight, but when they 

 are very large these are reduced to four or 

 two, or even one ; and in other cases their 

 number is greatly increased, so as in par- 

 ticular instances to be indefinite as far as 

 our powers of observation go. In a par- 

 ticular condition a large proportion of these 

 fungi produce also naked spores on distinct 

 plants, and occasionally naked spores and 

 asci are produced upon the samehymenfum. 

 The distinction from sporigerous fungi is 

 not therefore as definite as might be 

 wished, though the group is strictly na- 

 tural. Some of the species approach the 

 lichens so nearly as to be scarcely distin- 

 guishable. It is said that asci have been 

 lately found on the gills of one at least of 

 the higher fungi, Agaricus melleus, which 

 is largely consumed abroad under the title 

 of halimasch, though justly neglected 

 here. This, however, wants confirmation, 

 and an assurance that some parasite is not 



in question. Some of the moulds again 

 produce fruit containing a single spore, 

 or a number of asci; but whether these 

 moulds are true allies of the Ascomycetes 

 or not is at present doubtful. The Morel 

 is one of the most familiar examples of 

 the division, and one of the most highly 

 organised. The Truffle belongs to the 

 same division, though so different at first 

 sight from its near allies. [M. J. B.] 



ASCOPHORA. A genus of vesicular 

 moulds (Physomycetes), differing from Mu- 

 cor principally in the head being ac length 

 flaccid and hanging over the top of the 

 stem like a cap or bonnet. The Bread- 

 mould belongs to this genus, and there 

 are one or two more species of some con- 

 sequence. A singular fact about some of 

 the species is that the fruit upon the sides 

 of the stem is different from that at the 

 apex, retaining its globular form, and con- 

 taining sporidia of a different size. Asco- 

 phora elegans is a most beautiful object, 

 from the repeated and regular forked 

 branching of the lateral threads, each divi- 

 sion of which is terminated by a fertile 

 vesicle. The Bread-mould is easily culti- 

 vated, and the whole developement of the 

 plant in consequence readily traced. Other 

 species, like A. elegans, may be cultivated 

 on rice paste under a bell glass, and are in- 

 teresting objects of study. [M. J. B.] 



ASCYRTJM. A genus of the St. John's 

 wort family (Hyper icacece), numbering five 

 species, all of them American, with a dis- 

 tribution from the K United States south- 

 wards to N. Grenada. All the species have 

 been cultivated in Britain, and one of 

 them (A.CruxAndrece) is called St. Andrew's 

 Cross, from the circumstance of the four 

 pale yellow petals approaching each other 

 in pairs, so that they appear like a cross 

 with equal arms. Collectively, they are 

 called St. Peter's worts, to distinguish them 

 from St. John's worts. [A. A. BJ 



The species are all under-shrubs, re- 

 sembling the St. John's worts in general 

 appearance, having opposite sessile leaves, 

 sprinkled below with black dots, and large 

 terminal yellow flowers, singly or three 

 together. The genus is characterised by 

 the tetramerous (four-part) arrangement of 

 the calyx and corolla; the two exterior 

 sepals of the persistent calyx much larger 

 than the inner pair ; the deciduous petals 

 cruciate and widely-spreading ; the stamens 

 indefinite, from nine to a hundred, with 

 slender filaments, and ovoid two-celled 

 anthers ; the ovary ovoid, one-celled and 

 two to four-lobed, with as many styles, 

 and numerous ovules ; and the capsule en- 

 veloped in the enlarged calyx. [W. C] 



ASEROE. A genus of phalloid Fungi, 

 distinguished by the bifid rays of the re- 

 ceptacle. The species, which may probably 

 be reduced to three, are of a delicate pink or 

 green. They vary greatly in the degree to 

 which the rays are divided. Like others 

 of the group, they are very fetid when 

 fresh. They are confined to the islands of 

 the southern hemisphere. The genus de- 



