580 STUDIES IN FOSSIL BOTANY 



were probably borne in the same fructification with the 

 ovules. This suggestion has been completely con- 

 firmed by the investigation of the perfectly preserved 

 specimens which have since come to light in America. 



The male sporophylls of the Bennettiteae were first 

 discovered in 1899, m tne Dakota species Cycadeoidea 

 ingens, already referred to ; l their relation to the 

 gyna^cium was established two years later, in the same 

 species, when the organisation of the hermaphrodite or 

 bisexual flower was described for the first time. 2 Twenty- 

 five trunks with bisexual fructifications, belonging to 

 seven American species, have now been investigated. 

 The fructifications were borne laterally on the stem, 

 precisely in the same way as those of Bennettites Gib- 

 sonianus and other European forms, which were prob- 

 ably also bisexual (see p. 588). The plant bore a 

 considerable number of fructifications at the same time 

 (see Fig. 1 99) ; on a single specimen of Cycadeoidea 

 dacotensis sixty-one fruits, all more or less at the same 

 stage of development, were counted, and Dr. Wieland 

 is inclined to think that the plants were " monocarpic,'' 

 fruiting once for all and then perishing, as is the 

 case with many Palms and Bamboos at the present 

 day. 



The structure of the bisexual fructification or 

 " flower," as it may be appropriately called, will first be 

 described in the case of Cycadeoidea dacotensis, one 

 of the species most fully investigated. It may, how- 

 ever, be said at once that no important differences in 



1 Wieland, "A Study of some American Fossil Cycads, Part i. The 

 Male Flower of Cycadeoidea" Amer. Journ. Science, vii. 1899. 



2 L.c. Part iv. ' ' On the Microsporangiate Fructification of Cycadeoidea," 

 Amer. Journ. Science, xi. 1901. 



