67 
And in recent years the Engler System has been assailed by 
certain North American* and Britisht botanists who have 
devoted special attention to the subject. Opinion in America 
in particular seems to have changed rapidly from an almost 
universal acceptance of the German system towards a modification 
of the arrangement of Bentham and Hooker which they had 
nearly abandoned. This criticism refers especially to the 
question of the relative one age of the various groups 
from which a start should made, such, for instance, as the 
position of the Amentiféras™ ” and other apetalous groups, and 
of the Monocotyledons. 
Bentham & Hooker's Genera Plantarum.—The system of 
Bentham & Hooker was probably never intended to express 
a complete phylogenetic scheme of classification, for it is but a 
more extended arrangement of Jussieu’s work elaborated as 
long ago as 1789, and further expounded by De Candolle in 1818, 
when botanists were still imbued with the idea of the fixity, of 
species, and long before they had the aid of the Darwinian theory 
of descent as their guide. 
erhaps Jussieu should be reckoned second only to Linnaeus 
in that he was the first botanist to co-ordinate the genera of 
plants into families more or less as we now know them. Although 
a few of the names of his groups are unfamiliar to present-day 
botanists, nearly all in a slightly modified form are still in use. 
Bentham & Hooker’s work was primarily concerned with a 
practical handbook to the genera of plants arranged in such a 
manner as best to facilitate their determination. For the 
moment, however, we may assume that Bentham & Hooker’s 
Genera Plantarum was intended to express a more or less natural 
system, and examine the arrangement of their main groups. 
They began with the Ses uses their first Order (Cohort) being 
the Ranales composed of the well known Ranunculaceae and 
allied families, characterised < apocarpy and hypogyny of the 
flower. From these they proceeded to a discifloral series and 
finally (in the Polypetalae) to the calycifloral perigynous and 
epigynous: types of flower. After these the Gamopetalae were 
enumerated, then the Monochlamydeae (Apetalae) and Gymno- 
sperms, and finally the Monocotyledons. In elaborating their 
system, if we may continue to call it such, they unfortunately 
retained the Monochlamydeae as a group apart from the Poly- 
petalae, and it is to this point and also to the anomalous position 
of the Gymnosperms that most criticism has been directed in 
the past. I use the word retained, for those distinguished authors 
were well aware of the true affinities of the families which compose 
these two unnatural groups. This is clearly seen by reference 
* See especially C. E. Bessey ° ‘ The phylogeny and taxonomy of ANG: 
sperms ” Bot. Gaz. 24; 145-178 (1897), and Ann. Missouri Bot. Gard, 2 
109-164 (1915). 
{E & J. Parkin, * The Origin of Angiosperms," Journ. 
Linn. Bie: Bot. 38; "99 (1907). 
A2 
