242 
next, whereas on the top a large number of the charac- 
teristic ovulate sporophylls are borne, intermixed with 
sterile bracts, the interseminal scales. 
When the seeds have become mature the microsporo- 
phylls have disappeared, and when they are present the 
female sporophylls are still in a very young condition. 
Thus we may call the whole fructification protandrous. 
The microsporophylls resemble strongly the long fernlike 
leaves, and are composed of an axis with about twenty 
slender pinnae, bearing two lateral rows of synangia at 
their undersurface. 
The macrosporophylls, however, are much more advan- 
ced from the fern type, and have already reached a high 
degree of specialisation. Each ovuliferous organ is formed 
by a long slender stalk, having at its tip a single erect 
ovule and is surrounded at its base by the interseminal scales. 
In connection with the Pteridosperms, where the seeds 
are borne terminally on thin stalklets, being the reduced 
remnants of a modified frond, it is generally accepted, 
we have to do here with the same feature. Thus the 
seed bearing stalk of the Bennettitean seeds may be 
regarded as the ultimately reduced megasporophyll. 
The internal structure of the seed is not known very 
completely. The integument is composed of an outer and 
an inner fleshy layer and a middle stony one. At the 
apex it forms the long micropylar tube, which protrudes 
from the surface of the enveloping scale-leaves. 
The nucellus is provided with a beak and a pollen- 
chamber, and innerside a megaspore with a heavy mem- 
“brane is developed. 
At the base the ovule is invested by a small dish- 
like cupule. 
