334 
Notes on Recent Literature 
xerophytic habit of the mature plant ( Phyllocactus, Cereus, Echino- 
cactus, etc.), the transition corresponds to Van Tieghem’s third 
type . 1 
From a theoretical point of view, the discovery of the Ane- 
marrhena type of transition among the Cactaceas is of great interest. 
It will be recalled that in Anemarrhena (a member of the Liliaceae), 
there are two bundles in the cotyledon. Passing downwards we 
find that each phloem group branches into two, while each xylem 
strand divides into three. The lateral xylem groups unite in pairs, 
and the result is a tetrarch root-stele. Miss Sargant’s examination 
of about sixty species belonging to the Liliaceae led her to “ regard 
the Anemarrhena type as primitive, and as the starting-point from 
which most, if not all, the vascular types characteristic of Liliaceous 
seedlings have been historically derived.” 2 She further concludes 
that this type “may very well be primitive among Monocotyledond 
in general as well as among the Liliaceae proper.” 3 
A type of transition closely recalling that of Anemarrhena has 
been also observed in Eranthis, among the Ranunculaceae. It will 
be recalled that this resemblance led Miss Sargant to believe in a 
real genetic connexion between Eranthis and Anemarrhena, and to 
suppose that they are descended from a common ancestor with two 
seed-leaves, each represented by a single trace in the hypocotyl. 
Her theory of the origin of Monocotyledons from a dicotyledonous 
stock, by the fusion of two seed-leaves into one, was largely sug¬ 
gested by the resemblance which exists between the seedling 
structure of Eranthis and Anemarrhena. In the former, the petioles 
of the cotyledons are united into a tube. Some stress is laid on 
this point, since it was supposed that this particular form of vascular 
symmetry had something to do with the partial union of the 
cotyledons in Eranthis, and their (theoretical) complete union in 
Anemarrhena. 
We may now consider the bearing of Miss de Fraine’s discovery 
of the Anemarrhena type of transition among the Cactaceae, upon 
the geophilous theory of the origin of Monocotyledons. The view 
that Miss de Fraine herself takes is that “It cannot be considered 
that the resemblance of Opuntia, for example, to Anemarrhena is 
the result of a close genetic relation between the two; nor can it be 
conceded that it is due to a response of two unrelated forms to 
similar conditions; hence we cannot but conclude that the resem¬ 
blance is accidental .” 4 She goes on to point out that, if this is so, 
there is no reason for regarding the similarity between Eranthis and 
Anemarrhena as anything but accidental also. Later on she adds 
1 Ph. van Tieghem. Traite de Botanique. 2nd French Edn., 
Paris, 1891, Vol. I, p. 782. 
(Van Tieghem’s types of transition are also enumerated by Miss 
Sargant in “ A New Type of Transition from Stem to Root in 
the Vascular System of Seedlings.” Annals of Bot., Vol. 
XIV, p. 634, 1900). 
2 E. Sargant. “ A Theory of the Origin of Monocotyledons, 
founded on the Structure of their Seedlings.” Annals of 
Bot., Vol. XVII, p. 4, 1903. 
3 E. Sargant. “ The Reconstruction of a Race of Primitive 
Angiosperms.” Annals of Bot., Vol. XXII, p. 169, 1908. 
4 l.c., p. 167. 
