Maryland Geological Survey 



317 



seed plants, and the cycads still further emphasize this resemblance to 

 ferns in their mode of fertilization, i. e., by means of ciliated motile 

 sperms. 



When we come to consider the method and organs of fructification of 

 the Mesozoic Bennettitales (so called), instead of finding them of a 

 simpler type, as we might expect, we find a much greater complexity, 

 while on the other hand the vegetative structures are simpler than is 

 the case in the existing cycads. The fructifications in the former as 

 exemplified in the genus Cycadeoidea are long axillary bodies inserted 



Fig. 7. — Restoration of an unexpanded bisporangiate strobilus with some 

 of bracts removed, about one-half natural size. (After Wieland.) 



in large numbers among the crowded leaf bases (see Cycadeoidea mary- 

 landica). About half their length is taken up by the peduncle or stalk 

 on which spirally arranged bracts are borne, and these completely invest 

 the essential organs (see fig. 7). Distad, this peduncle expands into a 

 receptacle from the rim of which springs a whorl of staminate, com- 

 pound, fern-like sporophylls on which the pollen is produced, not in 

 simple anthers, but in compound pollen-sacs comparable with the synangia 

 of the marattiaceous ferns. These Cycadeoidea " stamens " in their habit 

 suggest a comparison with the ovulate fructification named by Renault 



