246 DR. J. W. HESLOP HARRISON ON 



graph. The result is a variability curve of the most ordinary 

 type. And wherever the character lends itself to such treat- 

 ment, be it in the degree of biserration of the leaves, the 

 length of the styles, the number of setag on the fruit, the 

 number of glands per square millimetre on the underside of 

 the leaves or in any other feature, the result v^^ould be the 

 same. 



This being the case, it is clear that if a value representing 

 the condition of any given bush in respect to the sum of its 

 characters could be assigned to it, and such statistics be 

 collected for a host of closely allied forms, then these figures, 

 too, if plotted as a graph, would produce a normal curve of 

 variation. The natural outcome of the failure to recognise 

 this elementary fact in the description of new species on the 

 plan outlined above is that, for the most part, rose species 

 simply exist on paper and at best only apply to bushes lying 

 at the limits of the variation curve proper to their group and 

 at irregular points more or less remote from these; such 

 descriptions, therefore, are worthless. 



To meet the circumstances of the case, the scientifically 

 correct procedure ought to be, firstly, the collection and study 

 of innumerable forms, then the selection for description of 

 those falling at or near the crest of the Quetelet curve for 

 their variability, followed, to do full justice, by a careful state- 

 ment of the range and trend of variation as determined by 

 careful study in the field, completed by details concerning 

 the rose as it grows. Had this method been adopted, 

 independently of one's attitude toward the status of such 

 forms, the number of so called species would have been 

 enormously reduced. 



This brings us up sharply against the value to be attached 

 to such forms; are they species or are they not? If not, 

 what are they ? 



Anyone studying the roses as living or-;tnisms, paying 

 due attention to habit as well as structure, cinnot fail to be 

 impressed by the numbers of apparent!}' distinct forms 



