130 REVIEWS. 



closely related species. For example : to take one order, 

 while Ulihianthus mmor may well be considered as "not a 

 sufficiently constant form to rank as a race even," while Limo- 

 sella tenuifolia could rank for no more than a race, and while 

 Castilleia sej)tentrionalis and C. pallida^ we are now con- 

 vinced, however distinct in this single character, differ only 

 (and inconstantly) in the relative development of the galea, 

 we think it likely that Pedkidaris hmata, Willd., does not 

 rightfully merge in P. hirsuta this side of the glacial period, 

 although it perhaps may into P. Langsdorffii, and that into 

 P. Sudetica. But this is no place for criticisms upon the 

 limitation of species, upon which the opinions of botanists will 

 so greatly depend upon the amount of their materials, and 

 upon which the best considered opinions must be subject to 

 frequent revisal. Nor does the value of the present memoir 

 at all depend upon the settlement of such points. To the 

 philosophical naturalist, as to the archaeologist, just now the 

 most interesting and pregnant epoch of the world's natural 

 history is that immediately antecedent to the present, that 

 near past from which the present has proceeded, and upon 

 which so much light, from very diverse sources, is now being 

 concentrated: towards its elucidation the memoir we have 

 been considering is a very valuable contribution. 



ALPHONSE DE CANDOLLE ON THE VARIATION 

 AND DISTRIBUTION OF SPECIES. 



This is the title of a paper ^ by Monsieur De Candolle grow- 

 ing out of his study of the Oaks. It was published in the 

 November number of the " Bibliotheque Universelle," and 

 separately issued as a pamphlet. A less inspiring task could 

 hardly be assigned to a botanist than the systematic elabora- 

 tion of the genus Quercus and its allies. The vast materials 

 assembled under De Candolle's hands, while disheartening 



^ Etude sur VEspece, a V occasion d'une Revision de la Famille des Cupu- 

 lifers. Par M. Alphonse De Caudolle. (American Jourual of Scieuce 

 aad Arts, 2 ser., xxxv. 431.) 



