ZOOLOGY AND BOTANY, MICKOSOOPY, ETC. 95 



classifies as follows :— A. Stem-leaves with completely resorbed cell- 

 membranes in their upper portion (*S^. fimhriatum Wils., Girgensohiii 

 Euss.) ; B. Stem-leaves never with completely resorbed cell-membranes, 

 usually toothed at the apex (^S. Russowii Warnst., fuscum Klinggr., 

 tenellum Klinggr., Warnstorfii Russ., qu'mquefarium Warnst., acutifolium 

 Ehrh. ex p., suhnitens E. & W., molle Sulliv.). 



Rabenhorst's Cryptogamic Flora of Germany (Musci). — The two 

 most recently issued parts of this work (Nos. 9 and 10) are almost 

 entirely occupied by the family Pottiacese, which is divided into the 

 two sub-families Pottiese and Trichostomese, distinguished by the 

 structure of the mid-rib. The former comprises the genera Pterygo- 

 neurum, Aloina, Crossidium, Pottia, Desmatodon, Tortula, Dialytrichia, 

 and SyntricMa, the latter Timmiella, Hydrogonium, Leptodontium, Tricho- 

 stomum, Oxystegus, Leptobarhula, PleurocJisete, Tortella, Didymodon, and 

 Barbala. Each genus is illustrated by at least one beautifully executed 

 woodcut. 



Algae. 



Chromatophores of Phseosporese.* — Herr J. Eeinke has examined 

 the form and appearance of the chromatophores in a number of Phseo- 

 sporese, for the purpose of determining whether any character can 

 be derived from them that will be of use in classification. He finds 

 that, while in some instances a special form of chromatophore is 

 characteristic of all the members of a group, in other cases nearly 

 related species will differ widely in this respect. Thus both the genera 

 of ScytosiphoneaB, Phyllitis, and Scytosiphon, are characterized by the 

 presence of a single large oval or sometimes nearly rectangular chro- 

 matophore in the parietal protoplasmic layer of each cell. In the 

 Sphacelariacese and Laminariacese there are also general characters to be 

 derived from the chromatophores. In the Ectocarpacese, on the other 

 hand, the form and arrangement of the chromatophores are constant 

 within the species only, varying greatly in nearly related species ; and 

 the same is the case in Balfsia and Myrionema. 



Mode of Distribution of Algae.f — Herr W. Migula gives a list of 

 AlgsB and Schizophycese found attached to water-beetles, especially 

 Gyrinus natator, in a tarn at a height of 1050 metres. He believes that 

 these insects play an important part in their distribution. 



Genetic Connection of Draparnaldia g-lomerata and Palmella 

 uvseformis.l — Herr 0. F. Andersson has found a mass of Draparnaldia 

 glomerata in the spring, partly in the ordinary vegetative condition, 

 partly with resting-spores. These last consisted of round cells inclosed 

 in a membrane, identical in size, form, colour, and nature of the cell- 

 walls, with Palmella uvseformis Ktz. Every intermediate state between 

 the two occurred on the same plant, and it was evident that the two 

 were stages in the cycle of development of the same species. 



Inferior Alg8e.§ — In continuation of his previous researches on the 

 lower forms of vegetable life, M. P. A. Dangeard reviews the position 



* Ber. Deutsch. Bot. Gesell., vi. (1888) pp. 213-7 (1 pi.). 



t Biol. Centralbl., viii. (188S) pp. 514-7. 



t Naturvet. Studentsallsk. Upsala, Nov. 5, 1887. See Bot. Centralbl., xxxv 

 (1888) p. 3.51. 



§ Ann. Sci. Nat. (Bot.), vii. (1888) pp. 105-75 (2 pis.). Cf. this Journal, 1888, 

 p. 754. 



