EXPLANATION OF TERMS. 



499 



cations in this book : (a) Leveilld's term 

 for sporophore. (b) Same as stroma. 



(c) In Ascomycetes : stalk of a discocarp. 



(d) In Ascomycetes : same as pyenidium. 



(e) In Phalloideae : inner portion of 

 sporophore supporting the gleba. (f) In 

 Lichens : cup of the thallus containing 

 soredia. 



Rejuvenescence. Transformation of whole 

 of protoplasm of a previously existing cell 

 into a cell of a different character. 



Resin-flux (Harzsticke, Harzuberfiille). 

 Disease in conifer characterised by 

 copious flow of resin with ultimate death 

 of the tree, due to attack of Agaricus 

 melleus. 



Resting period. Period during which a 

 dormant or quiescent state is exhibited. 

 Same as involution-period. 



Resting-stage. Stage of dormancy or 

 quiescence. Same as in volution- stage. 



Resting state. Quiescent or dormant 

 condition. 



Rheotropism. Phenomena induced in a 

 growing organ by the influence of a cur- 

 rent of water. 



Rhizine. Same as rhizoid. 



Rhizoid. Delicate filiform or hair-like 

 organ of attachment. Same as rhizine. 



Rhizomorphous. Having delicate branch- 

 ing form like rootlets. 



Rind, (a) The outer layer or layers of a 

 Fungus-body. Same as cortex. In 

 Lichens : same as stratum corticale. 

 (d) The outer layers of the bark in a 

 tree with secondary thickening and some- 

 times all the tissue outside the active 

 phloem. 



Ring. Same as annulus. 



Ringworm. Disease of the skin due to 

 Trichophyton tonsurans, Malmsten. 

 Same as tinea tonsurans, herpes ton- 

 surans. 



Rudimentary (rudimentar). An organ 

 or member is rudimentary which remains 

 stationary at a stage of development in 

 which it is in every respect immature. 



Saprophyte. Plant living on dead organic 

 substance. Comp. parasite. 



Schizogenetic. Formed by separation of 

 tissue elements owing to splitting of the 

 common wall of cells. 



Sclerosed. Exhibiting sclerosis. 



Sclerosis. Induration of a tissue or a cell- 

 wall either by thickening of the mem- 

 branes or by their lignification, i. e. for- 

 mation of lignin in them. 



Sclerotioid. Resembling a sclerotium. 



Sclerotium. Pluricellular tuber-like reser- 

 voir of reserve material forming on a 

 primary filamentous mycelium from which 

 it becomes detached when its develop- 



ment is complete, usually remains dormant 

 for a time, and ultimately produces shoots 

 which develope into sporophores at the 

 expense of the reserve material. In 

 Mycetozoa the sclerotium is formed out of 

 a plasmodium and after its period of 

 rest developes a plasmodium again. 



Secondary mycelium. Rhizoid attach- 

 ments developed from the base of a 

 sporophore which are somewhat like the 

 normal mycelium of the species. 



Semen multiplex. Tulasne's term for 

 sporidesm. 



Septate spore. Same as sporidesm. 



Simple sporophore (Fruchthyphe, 

 Fruchtfaden). Sporophore consisting 

 of a single hypha or branch of a hypha 

 Same as filamentous sporophore 

 Comp. compound sporophore. 



Soredial branch. Branch produced by 

 the development of a soredium into a new 

 thallus while still on the mother-thallus. 



Soredium. In Lichens : single algal cell or 

 group of algal cells wrapt in hyphal tissue, 

 which, when set free from the thallus, is 

 able at once to grow into a new thallus. 

 Same as brood-bud. 



Soredium-heap. Same as sorus. 



Sorus. Heap or aggregation. (a) In 

 Synchitrieae : heap of sporangia devel- 

 oped from a swarmcell. (b) In Lichens : 

 heap of soredia forming a powdery mass 

 on the surface of thallus. 



Spermatiophore. Structure bearing a sper- 

 matium. 



Spermatium. Male non-motile gamete- 

 cell which conjugates with a trichogyne. 

 The male sexual function of all spermatia 

 is not yet demonstrated. 



Spermatozoid. Male motile gamete. 



Spermogonium. Receptacle in which 

 spermatia are abjointed. 



Spora cellulosa. Same as sporidesm. 



Spora composita. Same as sporidesm. 



Spora multilocularis. Same as spori- 

 desm. 



Sporangiolum. In Mucorini : small 

 sporangium produced in some genera in 

 addition to the large sporangium. 



Sporangiophore. Sporophore bearing a 

 sporangium. See sporophore. 



Sporangium. Sac producing spores endo- 

 genously. 



Spore. Single cell which becomes free and 

 is capable of developing directly into a 

 new bion. 



Spore-group. Same as sporidesm. 



Spore-plasm. Protoplasm of a sporangium 

 devoted to the formation of spores. 



Sporidesm. Pluricellular body becoming 

 free like a spore and in which each cell is 

 an independent spore with power of ger- 

 mination. Same as spore group, com- 



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