Affinities of Sntcliffia . 1059 
as Heterangium ; moreover, he suggests that * the whole course of evolution 
from the protostele to the more elaborate dialystelic type may have been 
gone through within the family’, i. e. ‘ the Medulloseae are their own inter- 
preters.’ Finally, Scott suggests the probability of a common origin for 
the Lyginodendreae and Medulloseae ‘ from a point not very far below 
the level of stems such as those of Sutcliffia and Helercinginm ’. 1 The 
great possibility of the origin of the Medulloseae from a group of 
Fern-like ancestors has thus received full treatment ; it is on the 
probable affinities in other directions that the new specimen appears to 
give further evidence. 
The question of the relationship between the Medulloseae and the 
Cycadaceae has been so fully discussed that it would seem superfluous to 
reopen the question, were it not for the fact that the new specimen of Sut- 
cliffia appears to throw additional light upon it. Two main theories have 
been held with regard to the origin of the anatomical peculiarities of the 
Cycads. Scott 2 considers that £ so far as the anatomy of the stem is con- 
cerned, Lyginodendron appears to come near the Cycads, for the general 
organization is of a similar character, and the mesarch structure of the bundles 
is still retained in the peduncles of the cones of some recent Cycads as well as 
in the leaves ’. He regards the Medullosean stem as anatomically different 
from that of recent or Mesozoic Cycadophyta ‘ in being polystelic (except 
in the protostelic Sutcliffia , which does not affect the question) ’. The 
extrafascicular cylinders found in certain Cycadean genera are ‘local 
peculiarities in the vascular system . . . due to anomalous distribution of 
the cambium ’ and are not to be regarded as of ultimate phylogenetic 
significance. 
A second theory deriving the Cycads from the Medulloseae has been 
advanced by Potonie , 3 and independently stated and elaborated by Worsdell . 4 
The view of Matte 5 differs from these observers in certain respects, for he 
considers ‘ les Cycadacdes comme derivees de Lyginodendrees ou d’une 
famille voisine par l’intermediaire des Medullosees ’. In a recent account of 
the Pteridospermae Chodat 6 summarizes his views of the relation between 
Medulloseae and Cycadaceae as follows : ‘Les Medullosees nous apparaissent 
done comme des Protocycadacdes ’ ; and he further states that ‘ il nous est 
impossible de trouver dans l’anatomie des Lyginodendron la moindre 
analogie avec celle des Cycadacees ’. The main reason for the last state- 
1 Scott : loc. cit., p. 64. Compare Studies in Fossil Botany, 2nd ed., Part II, p. 464. 
2 Scott, D. H. : Studies in Fossil Botany. 2nd ed., Part II, pp. 648-50. 
3 Potonid, H. : Lehrbuch der Pflanzenpalaeontologie. 1899, footnote on p. 168. 
4 Worsdell, loc. cit. The paper of 1906 contains a full resume of his views and the evidence 
on which they are based. 
5 Matte, H, : Recherches sur l’appareil libero-ligneux des Cycadacees. Caen, 1904, p. 21 1. 
6 Chodat, R. : Les Pteridopsides des temps paldozo'iques ; etude critique. Arch, des Sci. phys. 
et nat., t. xxvi, 1908, p. 38 and p. 17. 
