1909] CHAMBERLAIN—DIOON SPINULOSUM 411 
As yet I have obtained only one staminate cone, and that not from 
the field but from Professor TRELEASE, of the Missouri Botanical 
Garden. Where the speci- 
men came from could not 
be determined, except that 
it had been secured from 
the nursery of W. A. MANDA 
(S. Orange, N. J.), who had 
gotten it in a miscellaneous 
collection of unknown 
sources. This cone, which 
atrived in Chicago July 25, 
1907, measured 21°" in 
length by 10°™ in diameter, 
and since the pollen was 
nearly mature, this must be 
about the size before the 
elongation of the axis begins 
to separate the sporophylls 
and liberate the pollen. 
The general appearance of 
the cone is shown in fig. 7. 
The shape of the micro- 
sporophyll and its general 
appearance is about as in 
D. edule, except that the 
microsporangia are much 
more numerous, the aver- 
age number on a micro- 
sporophyll being about 750; 
while in D. edule the average 
falls a little below 300. The 
number in D. Purpusii is 
between 300 and 4oo. In 
all three species the sporan- 
Fic. 7.—Dioon spinulosum; staminate cone 
rom a plant in the Missouri Botanical Garden, 
x 
July 1907. 
gia are in sori of 3, 4, 5, and 6 sporangia, with 4 and 5 the most 
frequent numbers. 
