No. 3, Decbmbbb, 1920] MORPHOLOGY AND TAXONOMY OF BRYOPUVH L75 



single comprehensive species, under which he frequently distinguishes subspecies, varieties 

 and forms. In many cases these subspecies, varieties and even forms are recognized as 

 distinct species by other writers, the following subspecies for example belonging I 

 category: Pellia epiphylla subsp. Neesiana; Lophozia ventrico pp. guttulata (Lindb. 



& \rn.i, longidens (Lindb.), confertifolia (Schiffn.), and longiflora (Nees); L. alpestris subsp. 

 Wenzelii (Nees); Scapania curta subsp. helvetica (Gottsche ; S. dentata subsp. undulata (L.); 

 S. aequiloba subsp. aspera (Bernel i; and Anthoceros punctatus subsp. Husnoti (Steph.). All 

 of these subspecies, an occasional variety, and the majority of the forms recognized by the 

 author represent new combinations (in the nomenclatorial sense), although this is not indi- 

 cated in any way. The work is designed primarily for beginners but will be of value to all 

 students of the Hepaticae. — A. W. Evans. 



1208. Monckton, Horace W. The flora of the Bagshot District. Jour. Botany 57: 

 251-257. 1919.— See Bot. Absts. 4, Entry 1717. 



1209. Pottier, Jacques. Sur la generalite de Pasymetrie foliaire chez les mousses. 

 The occurrence of foliar asymmetry in the mosses.] Compt. Rend. Acad. Sci. Paris 170: 

 471-474. 7 fig. 1920. — A study of sections of leaves of Leucobryum vulgare shows that the 

 dorsal side of the leaf develops more rapidly than the ventral, the leaves thus becoming 

 unsymmetrical. — C. II. and W. K. Farr. 



1210. Rickett, H. W. The development of the thallus of Sphaerocarpos Donnellii Aust. 

 Araer. Jour. Bot. 7: 182-194. 4 pi., 1 fig. 1920. — The author discusses briefly the somewhat 

 conflicting views of previous students of this genus. In the species studied by him, he finds 

 that the spore germinates by a slender germ tube, the details as to the formation of which 

 are very variable. On the end of this tube and at right angles to it a germinal disc is formed 

 by the activity of all the terminal cells of the tube, rather than by a single apical cell. This 

 disc develops into the thallus of the mature plant. Apical growth of the thallus is due to a 

 group of four-sided cells at the apical notch, although the author suggests the possibility that 

 but one apical cell may sometimes be present. The dorsal ,and ventral segments of these 

 apical cells add to the thickness of the thallus in the median portion. The lateral segments 

 produce the marginal lobes. Under natural conditions, these lobes are merged into a more 

 or less continuous rim. Under cultural conditions, the more rapid elongation of the median 

 portion of the thallus results instead in the production of distinct leaf-like lobes. Branching 

 of the thallus is due to a division of the apical group of cells into two such groups, a lobe occu- 

 pying the region between. The formation of lobes is not necessarily related to branching. 

 A detailed account of the history of two typical plants is presented. — E. W. Sinnott. 



1211. Warnstorf, C. Bemerkungen iiber einige Formen von Polytrichum und ihre Rip- 

 penlamellen auf der Oberflache der Blatter. [Observations on several forms of Polytrichum 

 and their leaf surface lamellae.] Hedwigia 61: 409-411. 1920. — Several forms of Polytrichum 

 attenuatum Menz. are noted, and a difference is demonstrated between the surface lamellae 

 of P. decipiens Limpr. and P. ohioense Ren. & Card. The author suggests a division of the 

 genus Polytrichum into four groups based on lamella characters. The following species 

 and varieties are described as new: P. attenuatum var. longifolium and P. decipiens var. 

 strictifolium from Germany; P. vaginatum from Greenland. — R. S. Nanz. 



1212. Warnstorf, C. Uber die vegetative Vermehrung einiger Laubmoose aus Bolivia. 

 [The vegetative reproduction of several mosses from Bolivia.] Hedwigia 61: 412-417. 1920. — 

 The author describes a method of vegetative reproduction by means of leaf fragmentation in 

 Prionodon luteovirens (Tayl.) Mitt., Tor tula aculeata Wils., Bartramia fragilifolia C. Mull., 

 and Leiomela deciduifolia Hcrzog. The last-named species also propagates itself by frag- 

 mentation of stems and branches. — R. S. Nanz. 



