472 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Bryophyta. 

 (By A. Gepp.) 



Vegetative Reproduction in Metzgeria.*— A. W. Evans discusses 

 the question of vegetative reproduction in Metzgeria. He describes the 

 gemmae of twelve species. 1. In five of them, 31. uncigera (Porto 

 Rico, new), 31. /areata Bum., 31. quadriseriata Evans, M. myriopoda 

 Lindb., 31. oligotricha (West Indies, new), the geinmaj are marginal. 

 2. In six the gemmae arise from the antical surface of the wings : 

 31. crassipilis Evans, 31. vivipara (Porto Rico, new), 31. Liebmanniana 

 Lindenb. & Gottsche, 31. dichotoma Nees, M. disciformis (New Zealand, 

 new), 31. linearis Aust 3. In one the gemmae are indefinite in posi- 

 tion : 31. fruticulosa Evans. Other species, including 31. conjugate and 

 31. hamata, seem to be entirely destitute of gemma;. Evans inserts 

 descriptions of his new species. He compares the gemmae of Metzgeria 

 with those of other Bryophytes, and shows that Riccardia (Aneura) is 

 the only thalloid genus in which the genmite are at all similar, while 

 certain foliose genera (Radula, etc.) have gemmae still more like those of 

 31etzgeria. He finally discusses the conditions under which gemmae are 

 produced — namely, conditions such as induce regeneration. There is a 

 kind of antagonism between the apical region and the other parts of 

 the plant. The apex has the first claim upon the nutritive processes ; 

 but when its activity is checked, then the other parts secure a higher 

 nutrition and exercise their latent faculty for producing gemmae. 



Androgynous Receptacles in Marchantia.t — E. M. Cutting gives 

 an account of some abnormal archegoniophores of 31archantia which 

 were partially antheridiiferous. He discusses its meaning, and cites 

 .nstances of a similar condition in other genera. 



Inter-relationships of the Bryophyta.J— F. Cavers begins a series 

 of papers on this subject by giving an account of the Marchantiaceae. 

 He sketches the distinguishing characters of each of the three groups — 

 Astroporae (4 genera), Operculatae (7), Composite (8). He then dis- 

 cusses the phylogeny of the whole group of the Marchantiales, epito- 

 mising his conclusions in a genealogical table. 



Regeneration in the Hepaticae.§— A. Coppey gives a resume of 

 W. Kreh's paper Ueber die Regeneration der Lebermoose.|| By re- 

 generation is meant the power possessed by isolated portions of plants 

 for putting out new shoots of a thalloid or of a foliose character, 

 according to the habit of the original plant. This regeneration is pos- 

 sible in all species studied, either from fragments of thallus, or from 

 ventral scales, or else from fragments of stem, leaves, perianths, arche- 

 gonia, from hairs or from very young rhizoids. In the acrogynous 

 Jungerniannieae the regenerated shoots are all of unicellular origin, 

 with or without a, protonema-stage. In the other families the shoots 

 may be either unicellular in origin, or pluri-cellular (and without proto- 



* Ann. Bot., xxiv. (1910) pp. 271-303 (figs.). f Tom. cit., pp. 349-57. 



X New Phytologist, ix. (1910) pp. 157-86 (figs.). 

 § Rev. Bryolog., xxxvii. (1910) pp. 59-62. 



|| Nova Acta Abh. k. Leop. Carol. Deutschr. Akad. Naturf., xc. (Halle, 1910) 

 89 pp.). 



