ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 197 



upon a prolonged and thorough soaking as necessary to restore the 

 primitive dimensions of the plant. 



Microthamnion.* — P. Hennings claims that the generic name Micro- 

 ihamnium Mitt, should be suppressed on the plea that Microthamnion 

 Naeg. was established in 184'J, that is 20 years earlier, for a genus of 

 Algae. Instead, he proposes Mitten othamnium. Also he claims that 

 Asterella is not available for a genus of hepatics as it was applied to a 

 genus of Fungi by Saccardo 10 years ago. 



Leaf-cells of Sphagnum.f — W. Lorch describes the comparative 

 development of the stem-leaves and branch-leaves of Sphagnum, and 

 the differentiation of the hyaline cells and the chlorophyll-cells. He 

 then passes on to the consideration of the perforations in the stem- 

 leaves of certain Sphagna. He divides the pores in the hyaline cells 

 into two groups according to whether they do or do not retain the 

 original shape in which they were developed. In the branch-leaves the 

 pores entirely retain the original shape ; but in the stem-leaves they do 

 not ; they assume all shapes, and there is often a complete or partial 

 resorption of the outer wall. Pores are produced during the bud-stage 

 on the under or convex side of the leaf ; but they do not appear on the 

 upper or concave side till later — and in some cases not at all. It is 

 essential to employ stains to render the pores visible. Methyl-blue and 

 methyl-violet act well. They stain the under but not the upper mem- 

 branes. This may be explained in two ways. Either the upper walls 

 are thinner than the lower, and contain less colourable material ; or the 

 (material of the upper membrane is different from that of the lower, 

 and probably this is the true explanation, because in the young leaf the 

 development of pores takes place on the under side only. 



European Muscineae4 — V. Schiffner gives an annotated list of nine 

 rare hepatics and one moss gathered in new localities in Austria by 

 J. Baumgartner ; and a second list of ten rare mosses and two hepatics 

 mostly gathered by the same collector and all from new Austrian 

 localities. 



A. Casares Gil § publishes a list of "25 hepatics and 45 mosses 

 gathered by himself in the neighbourhood of Barcelona, and mentions 

 five other mosses which he has failed to find but had previously been 

 recorded for the district. He adds some remarks upon the dryness of 

 the climate and its effect upon the moss-flora. 



Muscineae of the Atlantic Islands. || — V. Schiffner concludes his 

 contributions to our knowledge of the Muscineae of the Atlantic Islands. 

 He enumerates in all some 40 species of hepatics and 80 species of 

 mosses with numerous varieties. The novelties are three species and 

 one variety among the hepatics, and one species and three varieties 

 among the mosses. Several critical notes are introduced, and the dis- 



* Hedwigia, xli. (1902) Beil.l., p. 225. 



t Flora, xcii. (1903) pp. 84-97 (10 tips, in text). 



I Verb. d. k. k. Zool.-bot. Ges., lii. (19)2) pp. 708-11. 



§ Bol. Soc. Espafiola Hist. Nat., ii. (1902; pp. 327-33. 



J| Hedwigia, xli. (1902) pp. 273-94. 



