BOOKS AND CURRENT LITERATURE 191 



The establishment of alternation of generations of the type described 

 fills to a certain extent the tremendous gap between the Fucaceae and 

 the Phaeosporales, and clears up the hitherto doubtful homologies of 

 the former. Improbable as it seemed on the face of it, the Fucus plant 

 is really a sporophyte homologous with Laminaria, while the game- 

 tophyte of Laminaria corresponds to the cell-generations within the 

 oogonium and antheridium of Fucus. The gametophyte of Laminaria, 

 though much reduced, is an independent plant, while that of Fucus 

 reaches a stage even nearer total suppression than is shown in the 

 typical Angiosperm. It is as remarkable as it is unexpected that the 

 brown algae should show a series parallel to that of the archegoniates, 

 the more so since the evidence at hand indicates an antithetic origin 

 of the sporophyte in the higher plants, while in the brown algae there 

 is good reason to believe that the sporophyte is of homologous origin. 



If closer study confirms this interpretation of the facts, the Lami- 

 nariaceae must be classed with Fucus among the Cyclosporales, stand- 

 ing between the Cutleriaceae and the Fucaceae. — I. F. Lewis. 



Dicotyledonous Woods. — The interrelationships of the dicotyle- 

 dons are confessedly a tangle. Since 50% of the families are entirely 

 made up of wood}' plants, the comparative structure of the wood 

 ought to furnish facts of great value. But it has been found difficult 

 to say what diagnostic features are of phylogenetic value, and only 

 recently a beginning has been made in this direction. All that can 

 be said at present is to "report progress," as is evidenced by papers of 

 Adkinson,^ Hoar,^ Jeffrey and Cole,^ in addition to earlier papers from 

 the same laboratory. Plowman has contributed an illuminating com- 

 parison of the box elder with true maples,** in which he concludes on 

 anatomical and other grounds that "Negundo aceroides" became 

 segregated from Acer during the Glacial Period. — M. A. Chryslek. 



^ Adkinson, J. Some Features of the Anatomy of the Vitaceae. Ann. Bot. 

 27: 133-139. 1913. 



2 Hoar, C. S. A Comparison of the Stem Anatomy of the Cohort Umbeli- 

 florae. Ann. Bot. 29: 55-63, pis. 4, 5. 1915. 



Ibid. The Anatomy and Phylogenetic Position of the Betulaceae. Amer. 

 Jour. Bot. 3: 415-435. 1916. 



' Jeffrey, E. C. and Cole, R. D. Experimental Investigations on the genus 

 Drimys. Ann. Bot. 30: 359-368, pi. 7. 1916. 



■* Plowman, A. B. Is the Box Elder a Maple? Bot. Gaz. 60: 169-192, pis. 5-10. 

 1915. 



