ZOOLOGY AND BOTANY, MICKOSUOi'Y, ETC. 373 



elaters. A columella of this type strongly suggests the elaterophore of 

 PeUia, and an advancement in the sterilization of tissues in Marchan- 

 tiacete comparable with that observed in AnacrogynjB. The author 

 does not attribute this unusual occurrence to external factors, but con- 

 siders it to be the first stage in the tendency to break up the sporo- 

 genous mass. The initial separation of sterile cells at the apex may 

 occur even before the intrusion of the proximal part to form the foot, 

 or it may first be recognized at the time of initial elongation of the 

 sporogenous cells. The group of cells thus separated at the tip may 

 be added to either by the division of the wall cells or by periclinal 

 walls in the elongating sporogenous cells. This occurrence of a cap of 

 sterile cells at the apes of the capsule is likewise a feature appearing 

 prominently in members of the Anacrogynae, where in Aneura it 

 bears attached elaters. The occasional appearance of three or four layers 

 of sterile cells at the tip, and the convergence of the elaters, together 

 with the close relation they frequently bear to this point, are further 

 evidences pf transitional features from the diffuse arrangement of 

 elaters (as in other Marchantiaceae) to a definite organized structure such 

 as the elaterophore found in members of the Jungermanniales. A. G. 



Contribution to the Anatomy of Mosses.— H. W. von Danken- 

 SCHWEIL {Hedwigia, 1915, 57, 14-61, 3 tabs., 9 text-figs. ; also as a 

 Dissertation, Freiburg, 1915, 48 pp. See also Bot. CentralbL, 1917, 

 135, 392-3). The following results were obtained : — I. Pohjtrichiim 

 formosum. _ The rhizome exhibits : — 1. A bark (" Rinde "), consist- 

 ing of a thickened epidermis with rhizoids, beneath that two to three 

 layers of thin-walled cells, and still deeper a large-celled layer (" mit 

 3-Teilung "), called by the author endodermis ; all alive. 2. A central 

 part, of which the living cells form, as stereome, the principal mass 

 of the three-lobed central part, in addition to living uuthickened cells 

 on the margin of the central strand towards the endodermis ( = rudi- 

 mentary pericycle). The dead cells form " hydroids " (without contents, 

 occurring scattered in the central strand and in the rudimentary peri- 

 cycle), and " hypodermal " and " radial " strands ; these penetrate the 

 bark (" Rinde ") in three places. Inside the radial strands lie the 

 "leptoids," larger cells with somewhat wide ends, and amylome as 

 " auskleidung " of the indentations of the central strand in a stratum of 

 regular polygonal cells. The change from rhizome to shoot is very 

 gradual. In the shoot five strata are to be recognized : (1) strongly 

 thickened epidermis ; (2) thickened subepidermal zone ; (3) a well- 

 developed parenchyma of the bark— a " hydrom sheath" rich in starch, 

 and a layer with leptoids ; (4) a central strand with empty cells ; and 

 (5) true leaf -traces (four to five central cells, " deuter " of leptoid-like 

 form, and "comites"). II. Atriclmm undiilatum. The rhizome no 

 longer exists, ' merely an underground organ of simple structure, very 

 like the aerial green shoot. The central strand censists, however, of 

 living and dead cells. III. Mniuni has in the central strand a group of 

 empty cells, whose power of water conduction is certainly very slight ; 

 the leaf -traces end blindly, since they cannot draw enough water from 

 the central strand. IV. Funaria hygromotrica has a protective sheath 



