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. 
LlNDLEY, 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 Phy to graphic. 1 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 Systema Vegctabiliwn. 
DE CANDOLLE calls the units, which in such cases are 
treated as varieties, "Ics elements de I'espece"; 2 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 
1 ALPH. DE CANDOLLE, La Phytographie on I'art de decrire les 
vegetaux, 1880, pp. 74-82. Much of the argument set forth in the 
text is due to this excellent work. 
z Loc. cit., p. 80. 
