ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 53 



according to whether they seek or avoid shade or moisture, whether they 

 grow on rocks, stones, earth, sand, in streams, on cultivated ground, 

 damp meadows, ditches, bogs, forests, rotten wood, living trees, etc., 

 and secondly, whether they prefer chalk or silica. He then gives a 

 chapter on moss-formations, with topographical sketches. Taking the 

 Black Forest, he discusses in turn the species characteristic of the moun- 

 tain forest, the high moor, the sub-alpine rock region and streams, the 

 rocky gorges of the forest, etc. 



Flora exsiccata bavarica.* — The Royal Botanical Society of 

 Regensburg in Bavaria have issued a dried moss flora of Bavaria con- 

 sisting of 400 specimens in 16 fascicles of 25 specimens each. Four 

 fascicles appeared in each of the years 1901-1904. The work includes 

 mosses, Sphagnaceae, and hepatics, among them being duplicates from 

 the herbaria of P. G. Lorentz and L. Molendo in the Munich State 

 Herbarium. Assistance in preparation has been given by leading 

 specialists. 



Hygroscopic Properties of Mosses.f — A. Cserey has experimented 

 on the water-retaining powers of mosses, employing such common 

 species as Hypnum cupressiforme, H. purum, H. Schreberi, Hylocomium 

 loreum, H. splendens, H. triquetrum, Anomodon viticulosus, Dicranum 

 scoparium, Polytrichum formosum, and Sphagnum acutifolium. He 

 found that they absorb six times their own weight of water in less than 

 a minute, and require seven days to give it all up again. Hence they 

 play an important part in storing up on mountain slopes the excessive 

 rainfall which, in rushing away all at once, would work destruction ; 

 and also, by slow evaporation, they affect the humidity of the air. 



Biology of PolytrichaceEe.J — F. Quelle describes some of his ob- 

 servations on this subject. (1) The habit of the leaves forms two 

 types. On the one hand, P. piliferum, P. juniperinum, and P. strictum 

 have their leaf-margins so rolled inwards and connivent that the foliar 

 lamellae are exposed to daylight through a narrow slit only ; and the 

 leaves are consequently whitish-green. On the other hand, P. aloides, 

 P. nanum, P. umigerum, P. alpinum, P. formosum, P. gracile, and 

 P. commune, have the lamellae freely exposed to daylight, the narrow 

 leaf -margins when damp not being curved over the lamellae, though 

 incurved when dry. Too great evaporation is hindered by the obliquely 

 longitudinal curvature of the lamellate lamina. (2) Kerner's view as to 

 the closing mechanism of the capsule is incorrect. The peristome teeth 

 are not hygroscopic and do not bend, nor does the epiphragm sink or 

 rise in presence of moisture. The sporangium forms a sort of pepper- 

 pot both in damp and dry air, and is often directed horizontally. (3) 

 Though the inflorescence of Catharinea undulata is dioicous, yet if a 

 proliferation of the antheridial receptacle grows out it forms archegonia 

 at its apex. 



* Kartbaus Priill (Regensburg) : Dr. I. Familler, 1901-4, 16 Lief. ; see also 

 Hedwigia, xlv. (1905) p. 37. 



t Noven. kozlemenyek, iv. (1905) pp. 7-9. 



j Mitt, thuring. bot. Vereins, xix. (1904) pp. 17-22. 



