2 o8 
Notes on Recent Literature. 
placed in the Liliiflorse. Warming states (p. 102) that “ the 
Juncaceae may be placed first [among the Glumales] as they 
represent the typical trimerous flower [of the Monocotyledons] and 
have a capsular fruit ” ; and he traces an evolutionary sequence 
from the Juncaceae through trimerous genera like Cyperus, Scirpus, 
and Eriophorum to the more specialised genus Carex. Similarly, 
in the case of the Gramineae, the trimerous Bambusa, through 
genera like Oryza, connects the Juncaceae with the specialised 
Anthoxanthum, etc. 
Wettstein’s view that the Helobiae have given rise to the 
remaining orders of Monocotyledons does not appeal to us as being 
very convincing. We prefer, in this case, the view adopted by 
Lotsy that the Helobiae are an unsuccessful group in so far as they 
have probably given rise to no higher forms; and this also is the 
view adopted by Rendle. 1 
There seems, on the whole, to be a considerable amount of 
agreement among botanists that the Monocotyledons have been 
derived from the Dicotyledons; and, although the former do not 
attain the high vegetative and anatomical development seen in 
many of the latter, it seems right that the Monocotyledons should 
be placed after the Dicotyledons. It is not, however, to be expected 
that systematists will at present go to Lotsy’s extreme of dividing 
the Monocotyledons into two groups and placing these in different 
places among the Dicotyledons. In the distant future, it is possible 
that the Monocotyledons will disappear as a separate group; but 
much work remains to be done before such a drastic view can be 
adopted in systematic works, which rightly lag behind and act as a 
check upon the speculations of morphologists. 
One result of the prevailing view of the origin of the Mono¬ 
cotyledons from the Dicotyledons is that attention is now concen¬ 
trated on the latter group in the attempt to solve the problem of 
the origin of the Angiospermae. Lotsy discusses this question, but 
admits that he has no solution to offer. It is therefore most 
singular that his arrangement of the Dicotyledons—only the earlier 
parts of which appear in the present volume—should be on lines 
which assume that the problem has been settled, and settled in a 
definite manner. Lotsy has evidently no scruples such as we 
expressed in the concluding lines of the last paragraph : he seems, 
on the contrary, to regard his arrangement of orders as a spur to 
apply to morphologists to hasten the settlement of difficult and 
intricate problems. However, it is impossible to criticise Lotsy’s 
views of the Dicotyledons until his fourth and last volume has 
appeared. 
Both Warming and Wettstein recognise two sub-classes of 
Dicotyledons, the Choripetalae and the Sympetalae. The former, 
of course, are the Archichlamydeae of Engler; and Wettstein sub¬ 
divides the Choripetalae into the Monochlamydeae (beginning with 
Verticillatae and ending with Centrospermae) and the Dialypetalae 
(beginning with Polycarpicae and ending with Umbelliflorae). Neither 
Warming nor Engler adopts the latter sub-division. However, 
there is agreement by Warming, Engler, and Wettstein in placing 
first those monochlamydeous forms which have no obviously near 
relatives with dichlamydeous perianths. 
Whilst fully agreeing with the principle of this arrangement, 
' “The Classification of Flowering Plants” : vol. 1 ; 1904. 
