BRIEPER ARTICLES 
PRELIMINARY NOTE ON CERATOZAMIA 
With the aid of a grant made by the Botanical Society of America 
at the New Orleans meeting in December 1906, the writer has been able 
to secure material for a study of Ceratozamia in most phases of its life 
history. In September 1906 a trip was made to the barrancas of the 
Almolonga Valley near Xalapa, Mexico, where the plant is quite abundant. 
Photographs and field notes were secured and material was fixed for a 
detailed morphological and cytological study. Arrangements were also 
made for obtaining material at frequent intervals. 
In habitat Ceratozamia differs decidedly from Dioon, for Dioon is in 
the open, exposed to blazing sunlight, while Ceratozamia is in densely 
shaded places. The difference in light will be appreciated from the fact 
that a photographic plate which would be well exposed for Dioon in one- 
fifth of a second would require three minutes exposure for Ceratozamia. 
On the whole, Dioon and the plants associated with it are xerophytic; while 
Ceratozamia, though not found in wet situations, is associated with a 
luxuriant vegetation. 
Staminate cones which arrived in Chicago on March ro, 1906, shed their 
pollen within a week. Fertilization takes place more than a year after 
pollination. The first motile spermatozoids were observed June 9, 1906, 
and in the last week of June nearly every nucellus showed one or more pollen 
tubes in which spermatozoids were swimming. The spermatozoids were 
observed with diminishing frequency during the first two weeks in July. 
Swimming spermatozoids had previously been observed in Cycas by IkENo 
and in Zamia by WEBBER. Our observations add Dioon and Ceratozamia 
to the list. A section by LANG proves that the spermatozoid of Stangeria 
is also motile. Nothing is known of the pollen tube structures of the other 
four genera of cycads. 
The ovulate cones disintegrate and free the seeds soon after fertilization, 
while the embryo is still of the same diameter as the filamentous sus- 
pensor. The has no resting period, but growth is continuous from 
fertilization to the leafy plant—CHARLES J. CHAMBERLAIN, The Univer- 
sity of Chicago. 
137) {Botanical Gazette, vol. 43 
