SUMMARY. 81 
these numerous basal knobs of the cilia or the entire lens-shaped body 
from which they develop and a centrosome existing in previous cell 
divisions. In the case of Edogonium, furthermore, as pointed out by 
Strasburger, there would seem to be no centrosomes present, judging 
from the researches of Mitzkewitch, who figures the spindle as drawn 
to a point at the pole without a centrosome. Strasburger concludes 
that the lens-shaped thickenings on the plasma membrane from which 
the cilia develop in the case of Vaucheria, Gédogonium, etc., are 
to be considered the homologues of the blepharoplasts in Zama, ete. 
He says: 
This organ we will at once designate as a blepharoplast, as I consider it homolo- 
gous to the blepharoplasts of plant spermatogonia. The name was well selected; 
at least, I know of no reason for changing it.’ 
The development of sexually differentiated gametes is generally 
admitted to have taken place by development from swarmspores, and 
a study of plants showing early stages of sexual differentiation is thus 
of importance. Strasburger points out that in Volvox, which is such 
a plant, the cilia originate in a J/wndstelle similar to that of @dogo- 
nium, which he considers to be a blepharoplast. This derivation of 
the blepharoplasts of the Cycadacew from similar organs existing in 
lower plants is of the highest importance and indicates a general sim- 
ilarity in the mode of forming cilia in all motile reproductive cells. 
Many important points yet remain to be determined in regard to 
the blepharoplasts before the controversy regarding their nature can 
be finally settled. No final conclusion can be reached, furthermore, 
until our knowledge of the typical centrosome has been extended and 
systematized so that it is possible to state what constitutes a centro- 
some. If the writer by his efforts has in any degree aided in paving 
the way to an earlier understanding of the matter, he is satisfied. 
SUMMARY. 
(1) The researches have shown that there are at least two species of 
Zamia in Florida, where only one has heretofore been recognized as 
occurring. These are Zamia floridana DC. and Z. pumila L. It 
was found that neither of the forms studied could be referred to 
Z. integrifolia Jacq., as has been done heretofore, this being a very 
distinct West Indian species. 
(2) Zamia cones in various stages of development can be shipped 
by mail or express at least a three to five days’ journey, and arrive in 
perfectly satisfactory condition for microscopic embryological study. 
Material preserved in the cone for six to ten days, as this requires, 
has been carefully compared with freshly cut material and found to 
1 Dieses Organ wollen wir gleich als Blepharoplasten bezeichnen daiches fiir homolog 
den Blepharoplasten der pflanzlichen Spermatogonien halte. Der Name kann als 
gut gewahlt gelten, zum Mindsten sehe ich keine Veranlassung ihn zu iindern. 
5526—No. 2—01——6 
