150 
(BAILLON) ; and lastly to the Begoniacee” (BarLLon) in the unisexual flowers, 
in the inferior ovary, in the connate stamens, in the leaf- venation, in the 
placenta and in the exalbuminous seeds. Another instance of the transition 
from the Parietales to the Metachlamydex can be seen in the gamopetalous 
genera of the Theacar, such as Eurya and Anneslea. Moreover, some connec- 
tions may be found between the Parietales and the Ericales, when we compare 
the Stachyuraces” and Clethracese (BAILLON). As is stated above, the relation 
of the Parietales in one point or another to other series is of wide extent, 
reaching from the Salicales or the Centrosperme far up to the Cucurbitales. 
At one time we consider their gamopetalous character, and place them in the 
Metachlamydex. At another time their polypetalous genera make them. 
assignable to the Archichlamydex. The systematic position of the series should, 
therefore, be dynamic. As to the families in this series, it is absolutely 
impossible to arrange them serially, as they inter-relate one another like the 
methes of a net. To this fact, I shall return later on. What ENGLER mentions, 
in this case, partly confirms the above statement. He says” :— 
Eine solche Reihe wie die Parietales ist nicht ein einheitlicher 
monophyletischer Verwandtschaftskreis, sondern ein Complex von 
mehreren Verwandtschaftskreisen, die teilweise von verschiedenen 
Anfangspunkten ausgehend in ihrer Entwickelung auf derselben 
morphologischen Hauptstufe Halt gemacht haben, teilweise, wie die 
Wnterreihe der Flacourtiineae noch verschiedene Hauptstufen der 
Entwickelung erkennen lassen. 
But, when this series had been described by ENGLER as a complex of many 
groups, how then is it possible to give it a fixed place? The answer should 
decidedly be negative. 
Next, in EncLer’s system follow the Opuntiales®. As has already been 
stated, they hear resemblance in a greater or less degree to other series; to 
the Ranales in the spiral arrangement of the floral elements, to the Parietales 
in the structure of the ovary, and to the Centrosperme in the relative position 
of the sepals, petals and stamens. Consequently, their natural position changes 
from this place to that according to the way in which they are considered. 
1) Nacht. Pél.-fom. If—6, a, p. 133. 2) Le. IIL—6, p. 193. 
3) Eneren, A.— Erliuterungen, 1. c. p. 368. 
4) Evcrzr, A.— Erlauterungen, 1. c. p. 369. 
