SCHIZAEACEAE 



543 



to a dichotomous branching is not so clear. In the former the lowest pair of 

 pinnae are usually fertile, in the latter genus the sporangia may be distributed 



over the whole length of the leaf. 



Hairs are present in all the genera, and in all except Mohria they 

 are filamentous, as in the Botryopterideae, Marattiaceae, and Osmundaceae, 



Upper parts uf fertile leaves of the jjenus Sclnztii'a. A=Sc/:. />aiin</<i, S\v. /> 

 bifeda, S\v. C, D = Sc/t. f/i-gans. J. Sin. In /' tlie ultimate .-.e^menls are more strongly 

 magnified. (After Diels, from Engler and I'rantl, .\'nf. I\l1,i n ., 111,1111.) 



and are sometimes glandular. In Mo/iria they are no longer filamentous, 

 but flattened as scales : this condition, which is characteristic of most Ferns 

 of a more advanced type, is readily referable in origin to lateral widening 

 accompanied by longitudinal cell-divisions. 



The sporangia are not arranged in sori, but solitary, a number of them 

 being borne on each fertile segment. In Schizaea and A/ieiinia they 

 appear when mature disposed in regular rows, one on each side of the 

 midrib, on the lower surface of the fertile segments. They may be protected 



