ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 565 



A. Mannii normal and bud-bearing pinna-less leaves arise in alternation ; 

 in A. Mannii, the buds arise from marginal cells, and in A. obtusilobum 

 from the upper surface. In both these species the elongated rachis is 

 therefore monopodial with theoretically unlimited growth ; and in A. 

 obtusilobum, if the apex of this rachis is cut off the first leaf-rudiment of 

 the youngest bud becomes converted into a continuation of the pro- 

 liferous apex. The author then gives a list of numerous ferns grouped 

 according to the positions occupied by the buds on the leaves. 



Systematic Value of Sporangium-wall.* — K. Schnarf adds to our 

 knowledge of the structure of the sporangial-wall in Polypodiaceae and 

 Cyatheaceae, and discusses its systematic importance. He gives a brief 

 account of the use made by previous authors of the taxonomic characters 

 afforded by the sporangia, and expresses his opinion that the sporangia 

 of the Leptosporangiatas afford sufficient characters for a natural division 

 of the ferns, but that the annulus by itself is not enough, being in- 

 fluenced by external factors ; yet in combination with the structure of 

 the sporangial-wall it affords ample material for establishing the natural 

 relationships of the ferns. He describes in detail the structure of the 

 sporangium in all its parts, selecting Blechnum as a typical example. 

 Applying his ideas to Asplenium, he gives a list of many species 

 examined by him and arranged in five sections by Diels, and finds that 

 they are all characterised by similar sporangial characters, but that 

 Diplazium and Athyrium are entirely different, while Ceterach, Scolo- 

 pendrium, and Pleurosorus entirely agree with Asplenium. Other 

 botanists have reached the same conclusion in other ways. Similarly in 

 Cyatheaceae the author's theory holds good, but is more difficult of 

 application ; and he discusses the question as- to whether DicJcsoniece and 

 Cyathece ought to be united in one family. 



Gold and Silver Ferns.t— W. Zopf publishes an account of some 

 •experiments on the coloured secretions of the gold and silver ferns, 

 Gymnogramme chrysophylla, G. sulphured, G. calomelanos. By dipping 

 the fronds for an instant into neutral purified ether, he readily dissolved 

 these secretions, and obtained them in a pure state by distilling off the 

 ether. From the yellow secretion of G. chrysophylla and G. sulphured 

 he isolated two substances — a chrome-red crystallising aromatic body, 

 which melts at 159°, C 18 H 18 5 , and a neutral wax, which melts at 63°. 

 From G. calomelanos he obtained a colourless, crystallising body, with a 

 camphor-like smell, and melting at 141°, C 20 H 22 6 6 . They are not fatty 

 substances, nor are they resinous. Whether the wax comes from the 

 glands or from the epidermis, he has been as yet unable to determine. 



Tracheids in Node of Equisetum.J — M. G. Sykes has experimented 

 upon the tracheids found in the nodal region of Equisetum maximum, 

 and shows that their function is the conduction of water from the canals 

 of the internode on one side of the node to those of the internode on 

 the other side. This was demonstrated by forcing a solution of eosin 



* SB. k. Akad. Wiss. Math. Nat. Wien, cxiii. (1904) pp. 549-73 (1 pi.), 

 t Ber. Deutsch. Bot. Gesell., xxiv. (1906) pp. 264-72. 

 X New Phytologist, v. (1906) pp. 129-32 (figs.). 



