117 



Hemarthrta is reduced to a section oi Rotibcellia. Sorghum, 

 Chrysopogon and Heteropogon are made sections of Andropogon. 

 Zizanta miliacea, Michx., becomes Zizaniopsis miliacca^ Doell. 

 and Acherson. Calamagrostis includes two sections, Epigeos 

 and Deyeuxia. Ammophila he recognizes as having but one 

 species, A, artmdinacea. This excludes three North American 

 species which Bentham and Hooker included in Ammophila, w\z.: 

 A. longifolia, A, brevipilis and A. Curtisii, Vasey. These belong 

 to Dn Gray's section Calamovilfa of the genus Calamagrostis, as 

 defined in the Manual, and characterized by the hard parchment- 

 e, one-nerved glumes, and the absence of the sterile flower or 

 pedicel. They differ from A. arundinacca, Host, in the spicate 

 panicle, and the five-nerved rather scabrous glumes of the latter. 

 If, therefore, our species be placed in the genus Ammophila, ^^y 



■m 



must constitute a section Calamovilfa. They might very well 



lik 



form 



a new genus. 



Dactyloctenium, Willd., included by Bentham and Hooker in 

 Eleusine, is here retained as a genus. 



The genus Eremochloe\ Watson, receives the name Blephari- 

 dachne, Hack., because the name Eremochloa, Biise., given to an 

 East Indian grass allied to Hemarthria, antedates the name of 

 Watson, Triplasis, Beauv., is reduced to a section of Triodia, 

 Br. In this place I may remark that our Triodia seslerioides has 

 an earlier name, i. e. Triodia cuprea, Jacq., EcL ii., 21. Arcto- 

 phtla, Rupt, is here made a section oi Colpodimn, Trin., and the 

 genus Atropis, Rupt. reduced to a section of Glyceria by Bentham 

 and Hooker, is here again raised to generic rank. 



Geo. Vasey. 



New Contributions to our Knowledge of Sieve- Tubes. — ^y 

 Alfred Fischer.* 



The author has introduced a simple method which enables us 

 to obtain a more correct knowledge of sieve-tubes than we 

 have had heretofore. When a part of a plant is cut off, the fluid 

 in the sieve-tubes will partly flow out, and the current produced 

 in them will cause an entirely new arrangement of their contents. 

 The well-known illustrations of the sieve-tubes of Cucnrbita, etc., 



*Ber. d. K. Siichs. Ges. d. Wiss. zu Leipzig, Math.-phys. CI., r886, iii., iv., pp. 

 291-336, 2 pi. 



