the Embryos and Seedlings of the Cactaceae. 45 1 
includes the prostrate forms of which E. procumbens is a good 
type. The embryos of this species (Fig. 27) show a reduction 
in the cotyledons and in size, though they still appear Cereus- 
like. Of the third division I have no material : but in the 
fourth, slender creeping forms, E. tuber osns is the type, but 
its embryos resemble very closely those of the last-mentioned 
species. 
The development of the epicotyl in the few species in which 
I have followed it shows nothing remarkable, for the adults in 
this genus share the morphological simplicity of Cereus . The 
leaves at first show a tendency to fall into spirals, and the ribs 
appear relatively late. 
9. Genus Echinopsis. 
E. Zuccariniana , Pfeiff. and Otto. Figure 29. 
E. Eyriesii , Pfeiff. Figure 30. 
E. multiplex, Pfeiff. and Otto. Figure in Pfeiffer and Otto, IV. 
This genus is very close to the columnar Cerei, and really 
represents very short, many-ribbed forms of that genus. The 
germinated embryos as shown in E. Zuccariniana (Fig. 29) 
and E. Eyriesii (Fig. 30) possess remarkably slender coty- 
ledons and an almost globular hypocotyl. The former 
character suggests some relationship with Echinocactus \ and 
indeed Schumann in his recent monograph says, ‘ Die Gattung 
steht in der Mitte zwischen Cereus und Echinocactus. ’ The 
adult forms, however, certainly resemble the former much 
more closely than the latter genus, and it is probable that the 
connexion with Echinocactus is not closer than would result 
from a separation of Echinopsis from Cereus near where 
Echinocactus comes off from Cereus. In this connexion the 
embryos of E. cinnabarina , which Schumann considers as 
much Echinocactus as Echinopsis , would be of great interest. 
The epicotyl, as is common in the Cereus- like forms, shows 
nothing of especial interest. In E. multiplex eight ribs form 
at once without any stage with spirally arranged axillary 
clusters, showing how old and thoroughly fixed is the rib- 
producing character in this genus. 
