654 SUMMARY OF CURRENT RESEARCHES RELATING TO 



The chlorophyllaceous cells of the leaves of the branches are 

 compressed between the hyaline cells in one series on the inner, in 

 the other series on the outer side of the leaf, forming, on transverse 

 section, an isosceles triangle, with the free outer wall as its base. In 

 the hyaline cells that wall is in consequence more convex which is 

 more or less in contact with the adjoining hyaline cell at the apex of 

 the triangle, although there is never any actual mutual coalescence. 

 In the same species the prismatic form of the chlorophyllaceous cells 

 may be replaced by a triangular, oval, or even a trapezoid form. In 

 this mode of arrangement two groups may be distinguished : — 



1. The chlorophyllaceous cells are compressed between the 

 hyaline cells on the outer side of the leaf; the hyaline cells being 

 therefore more convex on the inner side of the leaf: — S. recurvum, 

 P. B., and var. speciosum Euss. (S. spectabile Sch.) ; Lindbergii Sch. ; 

 molluscum Bruch ; cuspidatum Ehrh. 



2. The chlorophyllaceous cells are compressed between the hyaline 

 cells on the inner side of the leaf; the hyaline cells being therefore 

 more convex on the outer side of the leaf: — S. acutifolium Ehrh. ; 

 rubellum Wils. ; Girgensohnii Buss. ; fimbriatum Wils. ; molle Sull. ; 

 Austinii Sull. ; papillosum and cymbifolium Ehrh., with its sub-forms 

 S. subbicolor Hampe, and glaucum v. Klinggr. 



3. In the remaining species of Sphagnum, the chlorophyllaceous 

 cells of the leaves of the branches lie exactly in the middle between 

 the hyaline cells ; either (1) free on both sides, when they are fusi- 

 form or disk-shaped in transverse section, and the hyaline cells 

 equally convex on both sides : — S. subsecundum, N. v. E. ; laricinum 

 Spr., and contortum Sch. ; or (2) the very small chlorophyllaceous 

 cells are elliptical in transverse section, and are equally enclosed on 

 all sides by the hyaline cells, which mutually coalesce : — S. Wulfianum 

 Girg. ; Ang stromi I Hartm. ; rigidum Sch. ; and medium. The squamosum 

 group presents some considerable deviations from this structure. 



Fungi. 



Leucogaster, a New Genus of Hymenogastrese.* — In beech- 

 woods in Hesse-Nassau, R. Hesse found a number of fungi belonging 

 to the Hymenogastrese, a group of Gasteromycetes which comprises 

 the genera Hymenogaster, Rliizopogon, Hysterangium, Hydnangium, 

 Gautieria, Octaviania, and Melanogaster. Among them he observed 

 a hitherto unknown form, which he describes under the name Leuco- 

 gaster liosporus, and regards as the type of a new genus which must 

 be placed between Melanogaster and Octaviania. It resembles 

 Melanogaster in the chambers of the gleba being filled with jelly in 

 consequence of the swelling of the basidia ; Octaviania and Hydnan- 

 gium in the form of the spores; but differs from all the other 

 Hymenogastrete in the structure of the membrane of the spores. 



The mycelium is not very massive, and consists of thin, at first 

 colourless, septated, branched hyphae with very thick walls and occa- 



* Pringslieim's Jahrb. wiss, Bot, xiii. (1882) pp. 189-94. 



