Horticultural and Systematic Varieties. 61 



type from which the rest would be merely derived forms. 

 Species of this kind are therefore obviously and avowedly 

 collective species. 



LiNDLEY, A. P. DE CaNDOLLE, AlPHONSE DE CaN- 



DOLLE and other eminent systematists consider the col- 

 lective species without Forma typica to be the only really 

 existing type. Species must be subdivided in exactly the 

 same way as genera, says the last named of these authors 

 in his Phytographie.^ Lindley splits up his species of 

 roses on the same principle ; Rosa rubiginosa into 8, R. 

 spinosissima into 9 varieties, etc. De Candolle deals 

 with the difficult and numerous subgenera and elementary 

 forms of Brassica in the same way in the second volume 

 of his Systcma Vegetabiliiim. 



De Candolle calls the units, which in such cases are 

 treated as varieties, "les elements de I'espece'' ;^ they are 

 related to the species as these are to the genera and as the 

 genera to the families. 



But the majority of botanists regard varieties as 

 forms which have been derived from the species. For 

 them the species is the type, the real entity, from which 

 the varieties have arisen by small changes. They follow 

 the course taken by Linnaeus who based his diagnoses, 

 in the vast majority of cases, on one of the forms of a 

 species and arranged the rest in a lower grade under 

 this. The origin of the varieties from the species was 

 simply inferred from a priori premises as I have already 

 shown in the first volume, this origin having only been 

 directly observed in isolated cases of horticultural prod- 

 ucts; for the majority and certainly the most important 



^ Alph. de Candolle, La Phytographie on I'art de dccrire les 

 vegctaiix, i88o, pp. 74-82. Much of the argument set forth in the 

 text is due to this excellent work. 



^Loc. cit., p. 80. 



