276 SUMMARY OF CURRENT RESEARCHES RELATING TO 



plates being divided into several well-marked compartments. To this 

 group belong B. pendulum, Warneum, and Broicnii (not B. Lorentzii, as the 

 author had previously believed) ; also B. Moei Sch. and B. Kaurini sp. n., 

 intermediate between the two latter. 



The second group is that of B. ardicum, under which species are included 

 a great number of subordinate forms ; it is characterized by the ventral 

 plates of the peristome being divided by a single median septum. In this 

 group the author described at length B. purpureuni sp. n., viride sp. n., 

 inflatum sp. n., helveticxm sp. n. A new species resembling this group in 

 the structure of the peristome, but ditfering in other characters, is described 

 under the name B. celandicum. 



Optical Properties of the Peristome of Mosses.* — If the peristome of 

 Braclujtliecium rutahulum is examined under the Microscope with polarized 

 light, M. J. Amann states that the teeth of the exostome will strongly 

 rotate the jjlane of polarization, and will become illuminated if seen with 

 crossed nicols. The endostome, on the contrary, does not possess this 

 property. If the peristome of a Barhula be examined it will be found to be 

 inactive. This action of the peristome on polarized light varies with the 

 genus ; it is feeble in Pottia and Weissia, rather more active in Grimmia, 

 more so in Dicranum, and considerably more so in Mnium and Hypnum. 

 The maximum of activity is observed in Braclujthecium, Camptothecium, &c. 



If a tooth from the exostome of Camptothecium lutescens be examined 

 with a power of about 500 diameters, it will be seen that it is not the whole 

 surface of the tooth that is illuminated, but that there are bands strongly 

 illuminated alternating with those less so. 



The author has found that a curious relation exists between the presence 

 of tannin and the optical properties ; those organs which contain the 

 largest percentage of tannin being the most active towards polarized light. 



Amblystegiuin.t — M. K. du Buysson describes thirteen European 

 species of this genus of mosses, and details the characters which dis- 

 tinguish it from Eurhyncliium, Brachythecium, Plagiothecium, and the 

 diiferent sections of Hypnum. 



Insectivorous Hepaticae.J — In his monograph of Physiotium Herr J. B. 

 Jack describes the arrangement of several tropical species (e. g. P. coch- 

 leariforme and giganteum) for capturing and feeding on insects. The 

 " trap " consists of a sac attached to the base of the ventral edge of some 

 of the leaves. In this sac is a fold which is pierced by an orifice. The 

 inner mouth of this orifice is protected by two small leaves, which effectually 

 prevent any small animals that have entered from passing out again. The 

 bodies of great quantities of insects and Crustacea were always found in 

 the cavity thus closed ; but the author was quite unable to detect any 

 organ or apparatus for their digestion. 



Mastigobryum. § — Herr F. Stephani gives a monograph of this genus 

 of HepaticsB, with descriptions of several new species. He then enumerates 

 all the known species of the genus, 169 in number, of which 41 are de- 

 scribed for the fii'st time. The sexual organs of a large number of the 

 species being unknown, they are necessarily classified from vegetative 

 characters, and he proposes the following 11 classes, viz. : — 1, Integrifolia ; 



* Bull. Soc. Vaud., xxii. (188G) pp. 157-61. 



t Buysson, R. du, ' Etudes sur les caracteres du genre Amblystegium,' 1885. See 

 Bull. Soc. Bot. France, viii. (1886), Rev. Bill., p. 162. 



X Jack, J. B., ' Monograph of Physiotium.' See F. Stephani in Rev. Bryol., xiii. 

 (1886) pp. 97-9 (1 pi.). Cf. this Journal, 1886, p. 830. 



§ Hedwigia, xxv. (1886) pp. 233-49 (2 pis.). 



