458 BOTANICAL GAZETTE [decemi^er 



In his discussion of the phylogeny of the cotyledon, Lyon^ concludes 

 that it is a sucking organ of the embryo derived from the so-called foot of 

 bryophytes and pteridophytes. His own summary is as follows: (i) The 

 typical embryos of the pteridophytes and angiosperms differentiate into three 

 primary members — the cotyledon, stem, and root; (2) cotyledons are not 

 arrested leaves but are primarily haustorial organs originating phylogeneti- 

 cally as the nursing-foot in the bryophytes and persisting throughout the 

 higher plants ; (3) the monocotyledonous condition is the primitive one and 

 prevails in the bryophytes, pteridophytes, monocotyledons, and some gymno- 

 sperms ; the two (sometimes more) cotyledons of the dicotyledons are 

 jointly the homologue of the single cotyledon of the monocotyledons ; (4) 

 the cotyledon always occurs at the base of the primary stem; (5) the hypo- 

 cotyl is a structure peculiar to the angiosperms, being differentiated between 

 the primary stem and root; (6) the so-called cotyledons of the pteridophytes 

 and gymnosperms, with the probable exception of Ginkgo and the cycads, 

 are true foliage-leaves. — J, M. C. 



Items of taxonomic interest are as follows : T. E. Hazen (Mem. 



Torr, Bot. Club II : 135-250. //y. ^o-^^. IQ02) has published a revision of 

 the Ulothricaceae and Chaetophoraceae of the United States. The species 

 recognized in the former family are 8 in Ulothrix, 7 (i new) in Stichococcus, 

 9 (2 new) in Microspora, and 3 in Tribonema ; in the later family the species 

 are 2 in iMicrothamnion, 13 (5 new) in Myxonema, 4 (i new) in Chaetophora, 

 4 (i new) in Draparnaldia, i each in Epicladia, Endoderma, and Bolbocoleon, 

 2 in Chaetosphaeridium, and i in Herposteiron. The 23 colored plates 

 illustrate the species very completely. — L. M. Underwood and W. R. 

 Maxon (Bull. Torr. Bot. Club 29: 577-584. 1902). in publishing an account 

 of a collection of Cuban pteridophytes, have described new species of 

 Alsophila, Polypodium, Asplenium, and Diplazium. — W. A. Murrill [idem 

 599-608), in his first paper upon the Polyporaceae of North America, has 

 presented the genus Ganoderma, recognizing 7 species, and describing 5 of 

 them as new.— M. L. Fernald (Am. Jour. Sci. IV. 14: 167-194. pi^- 5^^- 

 1902), in studying the relationships of some American and Old World species 

 of Betula. has united some ^veil-known trees and shrubs of the two hem- 

 ispheres. — J. M. C. 



Brebxer 9 has published a detailed, account of the development of the 

 stem in Danaea. Xhe author takes exception to the morphological terms 

 phloeoterma and siphonostele, proposed by Strasburger and Jeffrey respect- 

 ively, on the ground that they imply certain homologies which he is not 

 prepared to accept. As an alternative to these morphological terms, he 



8 Lyon, Harold L., The phylogeny of the cotyledon. Postelsia 1901 : 55-^6- 

 1902. 



9Brebner,G., On the anatomy of Danaea and other Marattiaceae. Ann. Botany 



