CURRENT LITERATURE 



BOOK REVIEWS 



North American gymnosperms 



Penhallow 



on gymnosperms. He has taken the North American species (exclusive of 



upon 



the anatohiy of the mature wood. The original plan had in view the identifica- 

 tion of material used for structural purposes; but the investigation soon included 



finally 



The 



final result includes detailed studies of 92 North American species, 21 Japanese, 

 and 4 Australasian. The enormous mass of detail to be sifted and organized 



ood 



be made evident can be imagined. 



two 



a 



Systematic." Under anatomy (192 pp.) a detailed account of the regions and 



gymnosperm 



bility, decay, and general phylogeny. In the systematic part (157 pp.) a s}Tiopsis 

 of the genera and species of Cordaitales, Ginkgoales, and Coniferales is presented, 



possible 



values. 



book 



the chapter devoted to phylogeny. The author has given an excellent illustra- 

 tion of the result of follovnng one set of characters in reaching conclusions as to 

 phylogeny. Morphologist s and paleobotanists and anatomists of a different sort 

 have done this before, and with results equally divergent. The morphologists 

 have been checked more frequently than the others, perhaps, for they have been 

 compelled to carry through many different structures that insist upon contra- 

 dicting one another in reference to any suggested phylogenetic connection. In 

 these latter days, ■however, morphology, anatomy, and paleobotany are beginning 

 to combine their results in any conclusion as to phylogeny, and the contradictions 

 are multiplying. Professor Penh.\llow has introduced another set of checks,- 

 which must either be incorporated in any general conclusions or explained away. 



recognizes 



upon 



combined with the others in the general result. When 



American g}-in nosperms 



certain 



Boston: Ginn & Co. 1907 



417 



