GneiaJean and Bennettitean Seeds. 
143 
Sections passing through the apex of the nucellus show four 
concentric rings of tissue—the perianth, the outer and inner 
integuments, and the border of the small lysigenous pollen-chamber, 
which at this stage is not much more than a shallow depression 
among the withered cells of the micellar apex. 
Turning now to Professor Lignier’s account of the seed of 
Beunettites Morierei , we find that it is described as possessing 
a micropyle free at the apex, but blocked lower down by a tissue 
which is regarded as the nucellar beak ; below this, the passage re¬ 
appears again, with walls which show signs of lysigenous 
Fig. 5. Transverse section of micropyle at lower level showing no 
definite internal epidermis, but a cavity apparently lysigenous. x 150. 
degeneration on the inner surface. Dr. Wieland, 1 however, finds 
in the American types a micropyle which is open throughout. This 
difference suggests that the micropyle of Bennettites became 
blocked after fertilization just as in Gnetum gnemon ; in that case 
the tissue known as the nucellar beak in Professor Lignier’s seeds 
would correspond to the secondary closing tissue in Gnetum, and 
Dr. Wieland’s figure might represent the seed of Bennettites at a 
younger stage. 
Professor Lignier himself draws attention in a note 2 to the like¬ 
ness of the Bennettitean ovule to a Gnetalean type of seed, but 
rejects this interpretation in favour of a Cycadean one, because, in the 
first place, the micropylar tube is solid at one point, and secondly, 
because the lower part of the tube does not appear to be lined by a 
1 Wieland, G. R. American Fossil Cycads. Washington, 1906. 
2 loc. cit. p. 50. 
