ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 383 



rhizome. 2. Axillary buds are regularly present in five species of 

 Botrychium. 3. The vascular connexions of the branches in Botrychium 

 vary widely with the species and with the individual specimen. It is 

 concluded that the details of the vascular supply of the branch are 

 controlled by the conditions of development, and are therefore of little 

 or no phylogenetic importance. 4. In wounded rhizomes of B. obliquum, 

 renewed activity of the cambium produces considerable masses of acces- 

 sory xylem ; the pith frequently develops sieve tubes and a cambium 

 which produces secondary xylem in quantity ; the pericycle often pro- 

 duces sieve tubes and secondary xylem. It is concluded that in this 

 species any stelar tissues capable of growth may produce vascular 

 elements under the influence of an injury. 5 The axillary bud of 

 B. obliquum arises as a plate of meristematic cells on the adaxial face of 

 the base of the very young leaf ; it develops without differentiation into 

 a plate of meristematic tissue one or two cells in thickness and 50-60 

 cells in area, which is buried by overgrowth of surrounding tissue. 

 6. The data secured are in agreement with the evidence pointing to a 

 relationship of the Ophioglossacete to the primitive ferns, especially the 

 Zygopterideae. 



Polypodium marginellum and its Allies.* — W. R. Maxon gives 

 an account of Polypodium marginellum and its immediate allies, a group 

 of the subgenus Ewpolypodium which is marked by a general structure 

 which is simple and unusual. The species are all epiphytes of moist 

 mountain forests and are closelv similar in o-eneral form, having fronds 

 which are narrowly linear, simple, 5-25 cm. long, pinnately veined, and 

 having the margin bordered w ith a capillary or flattish, lustrous, dark 

 brown or ebeneous band of imperishable sclerotic tissue. This sclerotic 

 band has no connexion with the tibrovascular conducting system, for 

 the veins terminate some distance from the margin. The function of 

 the band apparently is to give strength and rigidity to the fronds. This 

 band structure is not known elsewhere in Ewpolypodium. The case of 

 /'. gramineum is different, the dusky border being actually composed of 

 conducting tissue, consisting; of a marginal vein which connects the 

 excurrent ends of the branched lateral veins. Outside the marginal 

 vein is a delicate border of greenish tissue (which is not present in the 

 P. marginellum group). The author discusses six members of the 

 P. marginellum group, five of which are from tropical America and one 

 from St. Helena. Possibly also a "P. margineUum" collected in the 

 Canary Islands long ago by von Buch, may belong to the group. 

 P. Hessii from Porto Rico, and P. ebeninum from St. Helena, are 

 described as new to science. A synoptical key to the species is supplied. 



Asiatic Species of Polypodium.t — H. Takeda gives an account of 

 the Chinese, and some other Asiatic, species of the Pleopeltis section of 

 the genus Polypodium. In Christensen's Index there are about seventy 

 species of Pleopeltis alloted to temperate and subtropical Asia. Many 

 of these Takeda has investigated, and he finds that considerable reform 



* Bull. Torrey Bot. Club, slii. (1915) pp. 219-25. 



t Notes, Roy. Bot. Gard.. Edinburgh, No. 39 (1915) pp. 265-312 



