1904 ] CURRENT LITERATURE 237 
represent the essentiais of a contrivance for supplying the pollen chamber 
with water. The unique thing in Lagenostoma, however, is the peculiarly 
chambered integument. 
Professor Oliver also calls attention to the general resemblance of modern 
difference being found in the fact that only at the apex are nucellus and 
integument free from one another. Moreover, he describes the distribution 
of the vascular system in the cycadean ovule as probably derived from the 
vascular mantle found in the paleozoic seeds. He accounts for these differ- 
ences, and also for the fact that among the cycads the integument and nucellus 
are distinct only at apex, while among the paleozoic seeds they are distinct to 
the base of the ovule or nearly so, by assuming that between the original 
ovule and its insertion a new region has been intercalated, resulting in a 
retreat of the nucellar bundles from the pollen chamber. 
The remarkable case of Torreya is also introduced, whose anatomy sug- 
gests that it is the most archaic of living conifers, fuller details of which we 
are promised in a forthcoming memoir. Strong tracheal branches extend 
upwards from the tracheal plate at the base of the nucellus, and ultimately 
send branches into the nucellus which connect with a peculiar mucilage layer 
that may be a modification of the palaezoic tracheal mantle. It will be 
remembered that the other conifers have lost their nucellar vascular systems. 
About the time the preceding paper was going through the press, Mr. 
Oliver and D. H. Scott? made preliminary announcement that the peculiar 
seeds of Lagenostoma, described above, belong to the genus Lyginodendron, 
one of the Cycadofilices of Potonié. The evidence for the intermediate 
position of this group has been drawn entirely from anatomical vegetative 
characters, and the discovery of fructifications was looked forward to with 
peculiar interest. An undescribed species of Lagenostoma showed young 
seeds inclosed in a husk or cupule, whose peculiar glands and whose internal 
anatomical structure were only duplicated in the vegetative organs of Lygin- 
odendron. This genus, therefore, in its vegetative structure retains the inter- 
mediate position already assigned to it, but had fully attained the seed-habit. 
On January 21, 1904, the same authors® presented their full paper to the 
Royal Society, and in connection with a discussion of the systematic position 
of Lyginodendron proposed the establishment of a distinct class, under the 
name Preridospermae, to ‘embrace those paleozoic plants with the habit and 
much of the internal organization of ferns, which were reproduced by means 
of seeds.” The opinion was ventured that not only Lyginodendrae but 
*9OLIVER, F. W., and Scott, D. H., On Lagenostoma Lomaxi, the seed of 
Lyginodendron. Ann. Botany 17: 625-629. 1903. 
*® OLIVER, F. W., and Scott, D. H., On the structure of the paleozoic seed 
Lagenostoma Lomaxi, with a statement of the evidence upon which it is referred to 
Lyginodendron. Abstract preprint. 
