ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 627 



the region of the " Furos de Breves," and also contributes a general 

 account of the physical geography and vegetation of the area, illustrated 

 by a map, sections, and photographic reproductions. 



Arcangeli, Alceste. — II mimetismo nel regno vegetale. (Mimicry in the 

 plant world.) Atti d. Soc. Tosc. Set. Nat. (Pisa) Mentor., XIX. (1903) 



pp. 268-329 (1 pi.;. 

 Sestixi, Faust o. — Studi sulla composizione chimica delle Foglie del gelso. (Study 

 of the chemical composition of the mulberry-leaf.) 



Atti d. Soc. Tosc. Sci. Nat. (Pisa) Memor., XIX. (1903) pp. 330-9. 

 Vogler, P. — Variationskurven bei Pflanzen mit tetrameren Bluten. (Variation- 

 curves in plants with tetramerous flowers.) 



Vierteljahrsse.hr. Naturforsch. Ges. Zurich, XL VII. (1903) pp. 429-36 (4 figs.) 

 Wolf, E. — Neue asiatische Weiden. (New Asiatic willows.) 



Engler, Bot. Jahrb.. XXXII. (1903) pp. 275-9. 



CRYPTOGAMS. 



Bryophyta. 



Morphology of Muscineae.* — F. Vaupel endeavours to clear up some 

 morphological questions. As to the inflorescence of Mnium, he finds it 

 to be of compound origin, the first antheridium arising from the apical 

 cell, the latest segments of which are used up informing other antheridia. 

 It is also of compound origin in Polytrichum ; but here the apical cell 

 gives rise to the last antheridia. Certain cells of the paraphyses of 

 Milium and Polytrichum, and of the antheridia of the latter, form a 

 brown substance, the function of which is to collect water for the 

 benefit of the antheridia. As to the mechanism by which the anthero- 

 zoids of hepatics are expelled, it is by the swelling of mucous matter in 

 the antheridial-wall cells. The author also describes the structure of the 

 rhizoid-bundles of the Polytrichacege and shows that their function is 

 to conduct water as well as to attach the plant, and that they produce 

 buds. 



Rhizoids of Mosses.t — H. Paul joins issue with the views of 

 Haberlandt, and partly with those of Goebel, as to the function of the 

 rhizoids, and accepts those of Detmer. For he finds that the main 

 function of rhizoids is purely mechanical, namely to fasten the pro- 

 tonema or the plant or parts of the plant to the substratum ; and that 

 such other functions as absorption of water, &c, are subsidiary. As a 

 proof of this he notes that the rhizoids are most strongly developed 

 where they are most needed as organs of attachment, for instance in 

 epiphytic mosses. The existence of saprophytism in mosses he thinks 

 to be doubtful for certain reasons which he gives. As to saxicolous 

 species, it cannot be shown that their -1 rhizoids attack the stone ; it is 

 rather the water which is held in the tuft that dissolves the substratum. 

 The rhizoids of submersed species are thicker and stronger in proportion 

 to the strength of the current. Floating mosses have no rhizoids at all ; 

 and it is a strong argument that throughout the moss kingdom rhizoids 

 are not produced where organs of attachment are not needed. 



* Flora, xcii. (1903) pp. 346-70. 



t Engler, Bot. Jalirb., xxxii. (1903) pp. 231-74. 



