780 SUMMARY OF CURRENT RESEARCHES RELATING TO 



characters in the Bryophyta. The gregarious mosses are able to cover 

 large tracts of ground to the exclusion of almost all other plants, for 

 i sample, Rhacomitrium lanuginosum, species of Sphagnum, forms of 

 ffarpidium, Bryum associations on sand-dunes, Marsupella associations 

 on high mountains. In the chapter on the adaptive characters in the 

 gametophyte, Wheldon discusses the prctonema, the non-sexual methods 

 of propagation, the gametophore ; and then he treats of the sporophyte, 

 'The paper is of a very discursive character, teeming with field-notes and 

 observations. 



Allionella, a new genus.* — V. F. Brotherus describes and figures 

 Allionella, a new genus of mosses discovered in Ecuador by M. Allioni. 

 It is allied to Meiothecium, and is distinguished by its numerous shortly- 

 stalked sporogonia arranged along the upper part of the stem, with 

 theca erect and peristome of regular structure. The one species bears 

 the name AUioneUa cryphseoides. 



Austinella, a new genus.f — R. S. Williams gives a description and 

 figures of Austimlla, a new genus allied to Trichostomiim, but differing 

 in having leaves with a broad clasping base, and with the upper cells 

 angular and not papillose. It was originally found in Pennsylvania, 

 and named Syrrhopodon ? Rami by Austin in 1876. 



Leucobryum glaucum.J — E. M. Williams gives an account of the 

 unattached cushions of Leucobryum glaucum, which are sometimes found 

 under fir-trees and beech-trees, for example, in Fawley Woods, Hants. 

 They lie loosely on the dead - leaves, and are 1^ to 4 inches wide. He 

 agrees with W. H. Bun-ell's explanation of their existence, that they are 

 due to repeated disturbance by game-birds and other animals, whereby 

 alternating growth takes place on the two flattened sides; and the water 

 stored in the spongy tissue renders the tufts self-sustaining. But he 

 wonders why the cushions are not more common. 



Plagiothecium.§ — C. Meylan publishes some researches on the 

 monoicous forms of the sylvatico-dmticulatum group of the genus Plagio- 

 thecium. The published opinions of leading bryologists being much at 

 variance about the group, the author has collected material for yeais and 

 is now able to give an exact opinion about the value of each of the forms 

 in the group. The forms are divided into two series absolutely parallel, 

 but differing in the width of the leaf -cells. Series i. : cells wide, 10-20 /x. 

 Series ii. : cells narrow, 5-10 /x. To series i. belong the forms with 

 long capsules contracted below the mouth and having a long neck ; 

 while to series ii. belong the forms with short capsules having a short 

 conical or obtuse operculum. There is a correspondence between the 

 form of the leaves (acuminata and obtusifolia) and that of the cells. The 

 form obtusifolia always has the cells wider and shorter than those of 

 f. acutifolia. The number of male flowers is more variable in series i. 

 than in series ii. For the sake of clearness the forms in the group may 



* Oefv. Finsk. Vet. Soc. Foerh., liii. (1910) 4 pp. (1 pi.). 



t Bryologist, xiv. (1911) pp. 70-1 (figs.). 



I Journ. of Bot., xlix. (1911) pp. 318-19. 



§ Rev. Bryolog., xxxviii. (1911) pp. 67-9, 86-9, 109-12. 



