76 BOTANICAL GAZETTE [uty 
conica. ‘The results are different from those of IKENO in regard to the blepharo- 
plast and centrosome. He finds no centrosome in the mitoses preceding the 
mother cell of the spermatid, and believes that his failure to find one is due to the 
absence of such a structure and not to any defect in technique. Two blepharo- 
plasts were observed first in the mother cell of the spermatid near the plasma 
membrane, far from the nucleus. Escoyez does not consider the blepharoplast 
to be a true centrosome; yet he has not traced its origin, and whether it comes 
from within the nucleus or from a certain region of the cytoplasm is not settled. 
—S. YAMANOUCHI. 
Sorus of Dipteris.—Miss Armour‘? has studied material of Dipteris that 
included the younger stages of the sporangium. D. bijurcata showed simultaneous 
development of sporangia in the sorus, and D. conjugata sporangia of different 
ages. The former, therefore, conforms to BowEr’s “Simplices,”’ and the latter 
to his ‘“Mixtae.” The three species seem to make a series in the form of the leaf, 
with D. bifurcata as the most primitive, and D. quinquejurcata in an intermediate 
position; parallel with this is the division of sori, leading to increase in their 
number and decrease in the number of sporangia in a sorus; and finally there is 
the progression from the “Simplices” type to the “Mixtae” type. This series is 
thought to have progressed from such a type as Matonia.—J. M. C. 
Morphology of Symplocarpus.—RosENDAHL has investigated the embryo sac 
and embryo of Symplocarpus, and an abstract of his results has been published. 
The primordia of the flowers appear eighteen to twenty months before anthesis, 
the ovules being “formed” in the season (autumn) preceding pollination. The 
proembryo is of the massive type characteristic of the aroids, in this case i 
ovoid in form. There is a short suspensor, and the stem tip is organized in a 
groove of the proembryo which develops near the suspensor. The endosperm 
encroaches upon both integuments and even into the chalazal tissue; and in tum 
the massive proembryo (‘‘protocorm”) destroys the endosperm, so that finally 
_the embryo is freely exposed in the cavity of the ovary.—J. M. C. 
Proteases.—VinEs, in his fifth paper on this subject,? reports that oily seeds, 
those of hemp in particular, contain proteolytic enzymes which act vigorously 
without restraint from the oil present. He succeeded in isolating, for the first 
time from plant tissues, ‘‘a protease that is essentially peptic in its properties; — 
digesting fibrin to albumose or peptone, but not acting on albumose or peptone, 
whether produced by its own digestion of fibrin or added as Witte-peptone- Te 
facts justify the conclusion that the hemp seed contains two proteases, the on¢ . 
4° ARMOUR, HELEN M., On the sorus of Dipteris. New Phytologist 6:38 
figs. II-14. 1907. 5 
* ROSENDAHL, C. O., Embryo sac devel pment and embryology of Symp: at 
joetidus. Science, N. S. 272209. 1908. . 
= Vines, S. H., The proteases of plants. V. Annals of Botany 222103145" 
1908. . 
