Marc#H 8, 1901.] 
consequence of the fragmentary character of 
the material. For this purpose the fructifica- 
tion which, as also the stem, had a complexity 
of structure unknown in modern representa- 
tives of the Equisetinez, affords the most satis- 
factory basis, and the system proposed by 
Weiss, in which he makes use of such ex- 
ternal characters as scars, is shown to be of no 
value except for geological purposes. In Cala- 
mostachys Casheana the axis of the cone shows a 
secondary growth in the vascular system and 
thus gives a final negative to the view so strongly 
advocated by Brongniart, that secondary growth 
in the wood isa certain characteristic of the 
phanerogams. The Calamarieze show no tran- 
sitional forms with the Conifers, and can not 
be regared as their progenitors. In fact, our 
knowledge of these plants is at present so in- 
adequate, that we can not regard them as any- 
thing more than a highly organized family of 
the vascular cryptogams closely allied to the 
Equisetinez. But the question still arises if 
they show any affinities with any of the seed 
plants? If such affinity exists, it would prob- 
ably appear in the direction of the Coniferz or 
possibly of the Gnetaceze. The anatomy of the 
stem certainly approaches the former, while the 
structure and simple form of the leaf are not 
without significance. It is also true that the 
relative positions of the sporangiophore and 
bract in Paleostachys have been compared with 
those of the ovuliferous and carpellary scales 
of the Abietinez, but it is altogether probable 
that these examples are nothing more than in- 
teresting parallels in development which have 
no force in establishing relationships, and these 
latter must be sought in other directions, es- 
pecially as there are no transitional forms con- 
necting the two groups. 
The Sphenophyllez represent a group of the 
greatest phylogenetic interest, inasmuch as they 
occupy a position of which there is no repre- 
sentative among existing species. The genus 
Sphenophyllum constitutes a perfectly distinct 
group of which all the parts are well known in 
one species or another, and there is no longer 
room for the idea that these plants represent 
the foliage of a Calamite. Heterospory may 
have been present, but so far there is no direct 
evidence in support of such a view. 
SCLENCE. 
387 
The remarkable cones known under the name 
of Cheirostrobus pettycurensis have as yet not 
been found in connection with other parts of 
the plant, so that it is impossible to determine 
the exact nature of the organism to which they 
belonged. So far as known, however, they 
were homosporous, but the material now avail- 
able does not admit of final conclusions in this 
respect. It is nevertheless certain that these 
cones were of aremarkably complicated type, 
and while in the character of the sporangio- 
phores, and in the insertion and structure of 
the sporangia they exactly agree with the Cal- 
amarian type, the anatomy of the axis shows 
them to approach the Lepidodendroid lyco- 
pods, whence we may conclude that they rep- 
resent a synthetic type combining the characters 
of different groups of plants. 
From these facts Dr. Scott draws the infer- 
ence that the Sphenophyllalez were highly 
modified representatives of an ancient stock 
from which both the lycopods and the Equiseti 
have diverged, but our knowledge of these 
phyla rests at present entirely upon the evi- 
dence of fossil plants. 
In Lepidodendron, the well-defined presence 
of ligules serves to indicate a connection with 
Selaginella rather than with Lycopodium, a view 
which would seem to gain additional strength 
from the observed heterospory of Lepidostrobus 
Veltheimianus. Another feature of exceptional 
interest is the fact that in some of the cones of 
Paleozoic lycopods, the origin of which has been 
fully traced, an integument is formed about the 
macrosporangium in such a way as to produce 
a seed like body which eventually becomes de- 
tached, as exhibited in the well-known Cardio- 
carpon anomalum of Williamson ; and this de- 
velopment is repeated in Lepidostrobus, where 
the microsporangia are similarly invested by an 
integument. In this we obtain the first definite 
indication of those transitional forms which serve 
to connect the Cryptogams with the higher seed 
plants. 
The earlier views of Brongniart, which placed 
the Sigillarias among the Gymnosperms, are 
shown to rest primarily upon the fact that the 
first described Lepidodendron (L. Harcourtit) is 
devoid of secondary wood growth, and em- 
phasis is placed upon the now well-known 
