Apkil 28, 1905. J 



SCIENCE. 



675 



aceae. In their class Heterokontae the first 

 ' series ' purposely includes flagellate animals 

 {Chloramoeba, Vacuolaria, Chlorosaccus and 

 Chlorohotrys) ' since they represent the primi- 

 tive organisms possessing Heterokontan char- 

 acters, from which the next two series have 

 been derived.' The series Confervales in- 

 cludes such organisms as Chlorothecium, Mis- 

 chococcus, Ophiocytium, Conferva (of Lager- 

 heim) and Botrydium. These authors include 

 Vaucheria in a third series, thus widely sepa- 

 rating this genus from other Siphonales (in 

 the class Isokontae). This separation is not 

 followed by either West or Oltmanns, who 

 recognize the class Heterokontae as including 

 the Confervales only. 



On looking over the outlines of these four 

 systems, that of Blackman and Tansley strikes 

 one as quite the most radical. In order to be 

 understood the position of the authors as 

 stated in their introduction must be borne in 

 mind, as follows : " The most fundamental of 

 these modem conceptions is that which pro- 

 poses to regard the Algae as consisting of a 

 number of natural classes, phylogenetically 

 independent of one another, more or less par- 

 allel in evolution, and each derived separately 

 from the Flagellata. * * * These parallel 

 classes are generally to be distinguished from 

 one another by cytological characters, and 

 more especially by differences in the organiza- 

 tion of the zoospore, which is held to retain, 

 throughout each class, most of the charac- 

 teristics of its primitive flagellate ancestor. 

 The most conspicuous of these differentiating 

 characteristics of the zoospore are the nature 

 ot the assimilatory pigments, the character of 

 the chromatophore, and the arrangement of 

 the flagella." 



If we exclude the Diatoms and Charales it 

 is found that Engler recognizes 27 families of 

 green algae; Blackman and Tansley, 44; West, 

 28, and Oltmanns, 37. Clearly, the algologists 

 are no more agreed as to the limits of the 

 families of the green algae than they are as 

 to other points in the classification of these 

 organisms. 



THE CUP-FUNGI OF IOWA. 



In a recent number of the bulletins from 

 the Laboratories of Natural History of the 



State University of Iowa (No. 4, Vol. V.) 

 F. J. Seaver publishes a valuable paper on 

 the ' Discomycetes of Eastern Iowa.' In 

 preparation for this work the author collected 

 ' nearly one hundred species,' of which fifty 

 are now described, the remaining being ' re- 

 tained for further study,' in the hope that 

 they may appear in a later paper. The species 

 described are all old, the author having wisely 

 refrained from adding new species. The 

 books in which each species is described are 

 cited in connection with each description, the 

 lists resembling lists of synonyms, which they 

 actually are in some cases. The descriptions 

 and notes are good, and the plates (twenty- 

 five in number) are excellent. 



SEAWEED STUDIES. 



Professor Doctor J. J. Wolfe contributes- 

 a cytological study of the red seaweed Nema- 

 lion to the October number of the Annals of 

 Botany, accompanying his paper with seventy- 

 five well-drawn figures. In addition to work- 

 ing out very clearly the structure of the com- 

 plex chromatophore he finds reasons for con- 

 cluding ' that Nemalion presents the essentials 

 of an antithetic alternation of generations, 

 and that the cystocarp is, therefore, the homo- 

 logue of the sporophyte in higher plants.' 



Sargent's manual of trees. 



This important book has just appeared from 

 the press, and there has not yet been tijue for 

 the preparation of a complete review, which 

 must be deferred until a later issue. It need 

 only be said now that in a neat volume of 826 

 pages the author has described and figured 

 about 642 species and varieties, which occur 

 in North America north of Mexico. For the 

 first time the American botanist who is espe- 

 cially interested in trees has a portable manual 

 which he can use in every part of the country. 



Charles E. Bessey. 



The University of Nebraska. 



NATIONAL ACADEMY OF SCIENCES. 



The annual stated session of the National 

 Academy of Sciences was held in Washington 

 April 18-20, 1905. 



The following members were present during 



