74 BOTANICAL GAZETTE [JULY 
described. The results of Faull in the two former species are in the main 
confirmed, The last species is of interest because, like Osmunda cinnamomea, 
it has an internal endodermis surrounding the pith in the adult; but unlike 
the latter this does not appear in the young axis. The figures and descrip- 
tion of the authors leave some room for doubt as to the entire accuracy of 
of this statement, for they do not follow the central cylinder to a sufficient 
height in the sporeling to exclude their having missed the first appearance 
of the internal endodermis. Anadmirable résumé of the fossil Osmundaceae 
is given, from which it appears how unsatisfactorily meager is our knowledge 
of this interesting group of ferns, particularly on account of the paucity of 
specimens from the Mesozoic.— E. C. JEFFREY 
VARIOUS PERIODIC phenomena in connection with the growth and devel- 
opment of plants are well known. Many of these depend upon conditions at 
present wholly unknown and are designated, therefore, as autonomous. As 
illustrations may be cited the grand period of growth, the variation in the 
length of internodes and often of interfoliola (by which Miinter long ago 
designated the spaces between the pinnules on the common petiole), —Tammes™ 
has endeavored to determine the influence of the presence or absence of 
leaves upon some of these periodic phenomena. Thus he finds that if all 
leaves be removed from an annual shoot the periodicity in the length of the 
internodes is not disturbed, the elongation of the cells only being inter- 
fered with, so that the internodes remain shorter than in the living shoot. 
But the removal of one or more leaves does disturb the periodicity. Certain 
internodes have less length than in the normal shoots. One would expect 
that each leaf would affect only the growth of those internodes adjacent to it, 
but this is not the case, internodes above as well as below the removed leaves 
being influenced. Often more strikingly than the annual shoots the interfo- 
liola show a similar effect from the removal of leaflets.— C. R. B 
LipForss * has investigated the geotropic response of some spring plants 
whose geotropism is influenced by variations of temperature. These are 
almost exclusively plants which conclude their development before the 
warm season. He finds that many of these shdots at lower temperatures 
are diageotropic, while at higher temperatures they are apogeotropic. This 
he considers a typical case of dynamic anisotropism. Somewhat similar reac- 
tions, however, may be due to changes in temperature alone. In general 
those shoots whose geotropic reactions are influenced by alterations of tem- 
perature are more or less epinastic at lower temperatures, but this epinasty, 
which reaches its maximum a little above zero, disappears completely at tem- 
peratures above 20 degrees. At low temperatures darkness may also affect 
71 TAMMES, T., Die Periodicitat oe neepene bei den Pflanzen. 
Verhandl. Konigl. Akad. Wetens, Amsterdam, II. 3: 
* LipForss, B., Ueber den Geotropismus einiger F see are Jahrb. Wiss. 
Bot. 38: 343-376. Al. 3. 1902. 
