CHAPTEK XXVIII 

 THE SPERMATOPHYTES AND THE SEED HABIT 



340. The spermatophytes.* The division Spermatophyta 

 (meaning seed plants) contains not only the groups frequently 

 called " flowering plants " but also other groups which do not 

 have flowers in the popular sense of the word, for the repro- 

 ductive organs are borne in cones or clusters which are not 

 at all showy, but rather inconspicuous. These are, however, 

 flowers in the scientific sense, as are also the cones of the 

 horsetails and club mosses. The spermatophytes have also been 

 called phanerogams, or phcenogams (meaning evident marriage), 

 to distinguish them from all the lower groups of plants which 

 were called cryptogams (meaning hidden marriage). However, 

 this separation was made before the sexual processes of the 

 lower plants were understood, for as a matter of fact they are 

 much more evident than the complicated ones in the seed plants. 

 The seed is a more significant structure in the group than the 

 flower, so the name spermatophytes has in recent years come 

 into general favor. 



The seed plant, like the fern, is a sporophyte. There is a 

 gametophyte generation in the life history which is, however, so 

 much reduced in structure that it can only be understood 

 by a careful study of the reproductive processes in seed for- 

 mation. It is the main purpose of this chapter to make clear 

 the position of the gametophyte generation in the life history, 

 together with the origin and evolution of the flower. The struc- 

 ture and physiology of the sporophyte are considered in Part I, 



* To THE INSTRUCTOR : The introduction to this chapter assumes that the 

 life history of some seed plant, as the pine or lily, has been studied in the 

 laboratory. 



854 



