262 



The treatment of the ferns and fern-allies naturally shows an 

 improvement over the treatment given them in the sixth edition, 

 but one is left wondering what the authors conceive to be the 

 requirements for genera in these groups. Such closely allied 

 genera as ClicilmitJics 2jw^ Notholacna, Pcllacazwd Cryptograviina, 

 and Asplcniiiin and Caviptosonis gain recognition. On the other 

 hand, Afhvriiiui, now usually recognized as a legitimate genus, is 

 not given a place in the work, and Onoclea and Woodzvardia are 

 made up of most heterogenous elements. The writer, of course, 

 would not venture even to suspect an element of provincialism 

 in the continued use of Aspidinin, but does with becoming temer- 

 ity venture to suggest the expenditure of some of the income 

 from the sale of this work in the purchase of some genuine 

 Dicksonias ! Our North American plant so persistently referred 

 to these tree-ferns may then be allowed to take its legitimate 

 position. Again it may be suggested that while the treatment 

 of Lycopodium shows a clear understanding of the New England 

 species, the coastal forms of the inundatum-alopecuroides group 

 plainly need further study. 



One is glad, indeed, to see Aspleniiim ebcnoidcs definitely char- 

 acterized as a hybrid, and notes with satisfaction the more numer- 

 ous family groups now recognized. Isoetes and Eqzdsetwn have 

 been carefully elaborated by Mr. Eaton, and the resulting 

 arrangement is by far the best we have yet had for these variable 

 and difficult plants. How saddening it is to remember that Mr, 

 Eaton passed away almost simultaneously with the appearance 

 of the results of his labors on the groups he loved so well. 



Coming to the monocotyledons, one of the first genera which 

 will strike the reader is Potainogeton. The artificial key here 

 produced is apparently a very serviceable one and by not relying 

 too exclusively on winter buds and glands avoids being too 

 technical — a defect which makes Dr. Morong's key so difficult 

 for the field worker to handle. Many changes in nomenclature, 

 too, are made in this group, but these changes as well as the 

 changes required in SpaTgaiihun, Sagittaria, and other genera 

 placed early in the monocotyledonous series will generally com- 

 mend themselves. 



