384 



BENNETTITALES 



[CH. 



greater part of the seed-cavity: the micropylar tube is formed 

 of three layers, a strong inner palisade-layer, a thin middle layer, 

 and an outer palisade-tissue, the interior of the tube being filled 

 with parenchyma; at the shoulder of the 

 seed above the root-end of the embryo the 

 surface of the testa is characterised by 5 6 

 wings formed by the radial extension of 

 palisade-cells. After the shedding of the 

 spores and the abscission of the microsporo- 

 phylls the flowering shoot probably increased 

 slightly in length, thus pushing the ripening 

 seeds beyond the ends of the surrounding 

 leaf-bases. The ripe flowers were eventually 

 cut off by an absciss-layer immediately below 

 the receptacle (figs. 521, C, a\ 522, a), large 

 cuplike depressions being left on the surface 

 of the stem (fig. 534). The ovulate cone on 

 which the species Cycadeoidea Morierei is 

 founded probably represents the condition 

 of a naturally detached flower of a Cyca- 

 deoidea. It is possible that the detached 

 flowers freed from their encircling bracts 

 may have been edible, the small seeds being 

 dispersed by animal agency. 



FIG. 516. Cycadeoidea 

 Dartoni. Longitudinal 

 section of seed with 

 embryo. (After Wie- 

 land; x 19.) 



The splendid petrified stem, Cycadeoidea etrusca Cap. 1 , one 

 of the treasures of the Bologna Museum, was found on a tomb 

 20 miles west of that city where it was doubtless placed by the 

 Etruscans who obtained it from the Upper Jurassic scaly clays 

 in the Apennine Hills. It was in an imperfectly preserved 

 flower of this fossil that Graf Solms-Laubach discovered some 

 microspores, but it was not until Wieland's examination of the 

 more complete American stems that information was obtained 

 as to the spore-bearing organs. Another Italian stem, Cyca- 

 deoidea montiana Cap., was described in 1753 as a 'congeries of 

 barnacles 2 .' The specimen named by Goeppert Raumeria Reichen- 



1 Capellini and Solms-Laubach (92); Ward (96) p. 505. 



2 Ward (96) PI. civ. 



