Sketch of the Class Fungi. 



5 



which has been called peridium or pseudo-peridium, from the base of 

 which spring sporidia in moniliform rows, as in Peridermium, Mci- 

 dium, Endophyllum. 



The fungi of this order are, as stated above, Epiphytes or Ento- 

 phytes. The former, which grow on dead vegetables, are frequently 

 at first concealed under the epidermis, or amongst the woody fibres 

 which they burst or displace in order to continue their morphosis 

 externally. The Entophytes {Hypodermii, Fr.) pass through all 

 the phases of their development* under the thin bark of trees, or 

 under the epidermis of living or dead leaves, or of herbaceous stems. 

 It is only at the moment of the dispersion of the spores, or a little 

 before this epoch, that, rupturing the raised and distended cuticle 

 which covers them, they are exposed to the light, and receive from 

 atmospheric influences the completion of their development. What- 

 ever be the nature of the mycelium, its regular and normal morphosis 

 ends always in the production of the spores, the only aim of nature 

 in the formation of these singular productions, which have been com- 

 pared, and not without reason, to the Entozoa or intestinal worms 

 of animals. 



The sporidia, whether they arise from the metamorphosis of the 

 threads of the mycelium, or derive their origin from the matrix 

 on which they are produced, become at length free. Their forms 

 are numberless ; they are simple or articulate, that is to say, formed 

 of a single cell (Uredo), or several placed end to end (Puccinia, 

 Phragmidium) , or more rarely side by side in the same plane (Tri- 

 phragmium), constantly deprived of a common envelope (Corda, /. c. 

 p. 10). The sporidia, whether sessile or borne by a peduncle (hy- 

 popodium, Corda), and consisting of one or more cells, are, as regards 

 each cell, formed of a simple membrane (episporium simplex), as in 

 Uredo, or double (episporium duplex), as in Puccinia. In the latter 

 case, the two coats of unequal thickness which constitute the epi- 

 sporium are so intimately united, that it is impossible to separate 

 them; the outer is called exosporium, the inner endosporium. The 

 episporium is smooth, wrinkled, warty, hispid, &c, and encloses the 

 nucleus in its cavity. This, according to Corda, consists of a gela- 

 tinous fluid, in which are suspended a few oily globules, and in which 

 swim some granules, endowed, during the life of the plant, with 

 molecular motion, but which, as it approaches maturity, have a ten- 

 dency to become concrete. 



It is superfluous to add, that it is upon the infinite variety of 

 forms assumed by the sporidia and mycelium that the perhaps too 

 numerous genera of this family are founded. In this respect I 

 am of Fries's opinion, who says, Inter hypodermios maximam partem 

 (Coniomycetum) efficientes, typos nosse sufficiat, nisi singulorum mu- 

 tationibus in singulis plantis observandis vitam velimus dicare (Syst. 

 Myc. iii. p. 457). 



* Professor Henslow, who has lately paid great attention to the subject, 

 has satisfied himself that Aregma and Triphragmium are a more highly de- 

 veloped state of certain so-called Uredines. This too is probably the case 

 with Xenodochus. I am myself convinced that many of the browu Uredines 

 are merely an early stage of growth of certain Puccinia. — M. J.B. 



