Maryland Geological Survey 



315 



until vegetative maturity. It would follow, if the method just men- 

 tioned were pursued, that a BennetUtes which was not mature enough 

 to show indications of flowering would be a Cycadeoidea, or an accident 

 of preservation might equally determine the question, an altogether un- 

 desirable state of affairs/ 



It is very doubtful if specific determinations based upon external 

 form and surface features have any real value aside from their practical 

 utility, and it seems quite probable, as various writers have pointed out, 



Fig. 6. — Sketcli map of the world showing the approximate distribution of 

 the existing cycads. 



and as is fully admitted by Prof. Ward, that his determinations based 

 on megascopic characters cannot be looked upon as having real specific 

 value, but simply as the most expedient method of handling the immense 

 amount of material which passed through his hands, the specific names 

 affording convenient pegs on which to hang the morphological and 

 structural details which will result from a study of their histological 

 features. Nine species have been recognized by Prof. Ward in the 



^ See Wieland, Amer. Journ. Sci., vol. xxv, 1908, p. 97. 



