1904] CURRENT LITERATURE 479 
He finds three well-marked stages in the development: (1) a period of 
accelerating growth extending from the appearance of the stipe to the middle 
of the flowering period, 7-10 days; (2) a period of slow growth including 
the last half of the flowering sia ‘a development of the seeds, 6-8 
(3) a second period of active elongation reaching its maximum 1-2 days 
before the dispersal of the seeds and continuing for a day or two thereafter, 
7-10 days. The greatest daily growth noted in the first stage was 8.9™ 
and in the third stage 1o™. The curve representing the “grand period of 
growth’’ thus presents the anomaly of having two well-marked maxima. 
There seems to be no indication that external factors are responsible, as every 
individual measured, both in Japan and America, gave essentially the same 
results.— 
THE MEMOIR OF F. W. OLIVER® “On the structure and affinities of 
Stephanospermum,” read before the Linnean Society in February of 1903, 
has just appeared. In consequence of the fact that during this long interval 
between the reading of the paper and its publication a remarkable number 
of discoveries have been made bearing upon the matters of general mor- 
phological interest presented by this paper, its spurting is not so fresh and 
striking as it would have been a year ago.”° In addition to the details in 
reference to the two species of BT icc al considered, attention is 
called to the fact that the presence of a pollen chamber is a remarkably 
uniform character of paleozoic seeds. That this pollen chamber was asso- 
ciated with fertilization by means of swimming sperms seems to be no less 
evident, and it “reached its zenith in Permo-Carboniferous times. Its decline 
Professor Oliver correlates ‘‘with the evolution of pollen-tubes;" but it must 
be remembered that there is every reason to wie that pollen-tubes were 
not originally developed as sperm-carriers. The e paper is full of inter- 
esting details to the morphologist interested in ae ats of seed-plants, 
BOWER ~ has published the results of a study of a single specimen of the 
very interesting Sumatran Ophioglossum simplex, only three plants of which 
plant ee the very simplest elements, is the most peculiar feature in this 
species”’ is a statement from Ridley’s description. Bower found that an 
ternal examination revealed no part which could be compared with the 
eae lobe or ntl of other Ophioglossaceae, and this was confirmed by 
5 OLIVER, F. W., On the structure and affinities of Stephanospermum Brongniart 
a genus ae pa gymnosperm seeds. Trans, Linn. Soc. London. Bot. II. 6: 361-400. 
pls. 41-44. 1904. 
6 See Bot. GAZ. 37: 236. 
27 BOWER, F. O,, Ophiog: sa simplex Ridley. Annals of Botany 18: 205-216, 
pl. 15. 1904. 
