49 6 



EXPLANATION OF TERMS. 



Herpes tonsurans. Same as ring-worm. 



Heteroecious. Same as metoecious. 



Heteromerous. In Lichens : a thallus 

 with stratified tissue owing to algal cells 

 forming an algal layer and dividing the 

 hyphal tissue into an outer (rind) and an 

 inner (medullary) stratum is termed 

 heteromerous. Comp. homoiomerous. 



Heterosporous. Having asexually pro- 

 duced spores of more than one kind. 

 Comp. homosporous. 



Homoiomerous. In Lichens : a thallus 

 with algal cells and hyphae distributed 

 uniformly and in about equal proportion 

 is termed homoiomerous. Comp. heter- 

 omerous. 



Homologous. Having the same position 

 and development. 



Homosporous. Having asexually pro- 

 duced spores of only one kind. Same as 

 isosporous. Comp. heterosporous. 



Hydrotropism. Phenomena induced in 

 a growing organ by the influence of 

 moisture. 



Hymenial Alga. In Lichens: algal cell 

 in a sporocarp. Same as hymenial 

 gonidium. 



Hymenial gonidium. Same as hymenial 

 Alga. 



Hymenial layer. Same as hymenium. 



Hymenium. Aggregation of spore-mother- 

 cells, with or without sterile cells, in a 

 continuous stratum or layer upon a sporo- 

 phore. Same as sporogenous layer, 

 hymenial layer. S ee al so discus, lamina 

 proligera, lamina sporigera. 



Hymenophorum. Portion of a sporo- 

 phore which bears a hymenium. 



Hypha. The element of a thallus in 

 most Fungi ; a cylindric thread-like 

 branched body consisting of a membrane 

 enclosing protoplasm, developingby apical 

 growth and usually becoming transversely 

 septate as it developes. 



Hyponasty. That state of a growing 

 dorsiventral organ in which the ventral 

 surface grows more actively than the 

 dorsal surface. Comp. epinasty. 



Hypophloeodic. Of Lichens : living in the 

 peridermofaplant. Corrtp. epiphloeodic. 



Hypothallus. In crustaceous Lichens : 

 marginal outgrowth of hyphae, often 

 strand-like, from the thallus. Same as 

 protothallus. 



Hypothecium. Layer of hyphal tissue 

 immediately beneath a hymenium. Same 

 as subhymenial layer. 



Inception (Anlegung). First beginning. 



Inner peridium. See peridium inter- 

 num. 



Intracellular. Inside a cell. Comp. extra- 

 cellular. 



Interweaving (Verflechtung) of hyphae. 

 Union by intenvining without firm cohe- 

 sion with one another. 



Intralamellar tissue. In Hymenomycetes : 

 same as trania. 



Intramatrical. Inside a matrix or nidus. 

 Comp. extramatrical. 



Involucrum. Persoon's term for velum. 



Involution-form. Swollen bladderlike 

 form of Schizomycete, supposed to be 

 a diseased condition of the form with 

 which it is found associated. 



Involution-period. Same as resting 

 period. 



Involution-stage. Same as resting stage. 



Isogamy. Conjugation of two gametes 

 of similar form. Comp. oogamy. 



Isosporous. Same as homosporous. 



Kernel. In" Pyrenomycetes : old term 

 for the whole of the softer part of the 

 pyrenocarp within the firm outer wall. 

 Also termed nucleus. 



Lamella. In Hymenomycetes : vertical 

 radial plate on the under surface of the 

 pileus upon which the hymenium is 

 extended. Same as gill. 



Lamina proligera. Same as discus. 



Lamina sporigera. Same as discus. 



Lipoxenous. A parasite that leaves its 

 host and completes its development inde- 

 pendently, and at the expense of reserve 

 of food appropriated from the host is 

 lipoxenous. Comp. metoecious. 



Lipoxeny. Desertion of a host. 



Lysigenetic. Formed by disorganisation 

 or dissolving of cells. 



Macrogonidium. Large gonidium com- 

 pared with others produced by the same 

 species. Same as megalogonidium. 

 Comp. microgonidium. 



Madura. Disease in man characterised 

 by swelling and degeneration in feet and 

 hands and supposed to be due to 

 Chionyphe Carteri, Berkl., but the 

 causal connection is not definitely made 

 out. 



Malignant oedema. Disease in animals 

 like anthrax and due to a Bacillus in 

 form resembling Bacillus Anthracis. 



Marginal veil. In Hymenomycetes : a 

 membrane stretching from the margin of 

 the pileus to the surface of the stipe in 

 the young sporophore and covering over 

 the hymenium. Same as velum partiale. 

 See velum. 



Medulla. Central tissue within the rind 

 of a Fungus-body. In Lichens : same 

 as stratum medullare. 



Megalogonidium. Same as macrogo- 

 nidium. 



