34 The Ohio Journal of Science -[Vol. XX, No. 2, 



flowers of the head apparently bisporangiate but are really with 

 imperfect gynecia and, therefore, bear no seeds, while the mar- 

 ginal flowers are carpellate and seed-producing. All such com- 

 plicated arrangements of sexual expression arise in the ordinary 

 course of vegetative differentiation. Facts of this nature are 

 well known to systematists and must be taken into account by 

 all who would acquire an adequate conception of the sexual 

 relations and their developments in the higher plants. 



It is the careful study of the evolutionary changes and pro- 

 gressions in such diverse groups of the higher plants and ex- 

 haustive physiological and ecological experiments, especially on 

 those species that are in a transition condition from a bispor- 

 angiate to a diecious state, that will give a real insight as to the 

 nature of sex in Angiosperm sporophytes rather than isolated 

 studies on the cytology of species that have already reached 

 the goal of sexual segregation; Cytological studies can be made 

 an aid in the solution of the problem of sex if their pursuit is 

 not allowed to obscure the more fundamental basis of the 

 phenomena as presented by sexual plants in general. 



Ohio State University, Columbus. 



