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JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



in detail 137 species and varieties, besides indicating a few synonyms 

 and unnamed forms. When it is considered that these are all critically 

 and carefully described, this alone is sufficient to show how great is 

 the amount of work Major Wolley Dod has expended on his subject. 



But much remains to be done. He tells us, and it is obvious, that 

 he has left the work of classification to a later period. It is perhaps 

 somewhat to be regretted that in the circumstances he has not adopted 

 Baker's method, which has become familiar to students of the British 

 species. The arrangement he has selected is based on that of Keller. 



It is possible to say this and yet to admit that many of his re- 

 arrangements are fully justified. For instance, it is now generally 

 accepted that the Involuta and Hihernica groups ought properly to be 

 regarded as hybrids of spinosissima, the first with villosa and the 

 second with canina (or, as Crepin thought, with glauca or coriifolia), 

 but it is probable that w^hen the problem of classification is taken up 

 in earnest this process will have to be carried much further. 



The classification of Rosa is at once a most difficult and most 

 interesting study. Its difficulty, apart from the number of varieties 

 to be dealt with, arises from two distinct qualities of the rose. One is 

 that the powers of hybridization of species and varieties are so 

 immense that we seem to find all possible intermediate forms between 

 any two or more types, while the hybrid forms do not possess the 

 quality of sterility by which they may often be recognized to anything 

 like the same degree that usually obtains in other genera, and the 

 second is the considerable variation that may take place in the same 

 varieties in different 'situations by the process of adaptation, to en- 

 vironment. 



But the interest of the subject is hardly less than its difficulty, for 

 the solution involves some progress in unfolding of the laws of evolu- 

 tion. How and on what principle are we to define the limits of 

 apparently overlapping species, and how to determine the relative 

 importance of varieties? No doubt Major Wolley Dod is right in 

 saying that . an entirely new list of County records will be required. 

 A far more accurate and extended knowledge of the relative distribu- 

 tion of varieties, and the external conditions of soil, climate, and 

 situation under which they are found growing, seems of the first 

 importance in fonnulating a scientific classification. 



Grepin had suggested that it would be found that the ordinary form 

 of canina was replaced in the north and the mountainous districts by 

 R. glauca and coriifolia; this is confirmed by our author, who adds 

 to these the villosa group. Now the hairy character of the villosa 

 group is a protection against both cold and wet, and from this and 

 their sturdy habit it is easy to understand the prevalence of the Villosas 

 in these districts. Again, forms of the villosa group are often difficult 

 to distinguish from glauca and its congeners, so in this direction we 

 may perhaps find an explanation of Professor Orepin's observation. 



Further, we want more careful examination of the floral organs. 

 Malformation or want of virility in the pollen grains and imperfect 



