1912] CHAMBERLAIN—CERATOZAMIA - 7 
to hold in the hand. At the top of the cone the sporophylls often 
bear 3 spines and sometimes as many as 5 or 6, the arrangement 
and vascular connections making it evident that they are reduced 
pinnae. These sporophylls and some reduced sporophylls at the 
base of the strobilus bear no ovules. 
The young ovules are softly pubescent, but become perfectly 
smooth at maturity. 
They are small, seldom 
reaching more than 2.6 
cm. in length and 1.8 
cm. in breadth. When 
very young, and also at 
maturity, they are white, 
‘but during intermediate 
stages there is a delicate 
pink color, not very con- 
spicuous from the out- 
side, because the color is 
in the layer which is to 
become stony, and con- 
sequently is masked by 
the outer fleshy layer. 
The stony layer is much 
thinner than in Dioon, 
and can be cut with a 
pocket knife, even when 
the seed is ripe. There oe 
ings pitta the Gare of SoS CP 2, Si 4 Deere eotin 
the stony layer, as in age ducts; v, vascular bundles; X10; fig. 5, Por- 
Dioon edule, but rather tion of wall of microsporangium: d, dehiscence; 
«alt ght p roj ection, any t, tapetum; s, sporogenous tissue; 375. 
that the two species can be distinguished from each other by the 
character of the base of the stony layer. 
The general distribution of the vascular system of the ovule is as 
in Dioon; in the outer fleshy layer there is a system of unbranched 
bundles extending from the base of the ovule almost to the micro- 
pyle, and in the inner fleshy layer a system of bundles which branch 
5 ; : age Oy 
