A GENERAL SURVEY 19 



the purpose of the study it is necessary to make 

 comparisons between the reproductive schemes 

 of one of the highest flowerless plants, such as 

 a club moss, with the lowest types of flowering 

 species. Some of the most advanced types of 

 club mosses are to be found amongst the genus 

 Selaginella, whilst right at the end of the 

 flowering plants occurs the cone-bearing tribe, 

 usually spoken of as Gymnosperms. Actually, 

 the firs and their allies have many remarkable 

 features which make them very different from 

 ordinary flowering plants. One of the most 

 striking differences between the advanced 

 flowering plant and the members of the cone 

 tribe is to be seen when the female flowers 

 are examined. These are, of course, borne in 

 collections on cones, which are, however, quite 

 distinct from those producing the male flowers. 

 At the time of pollination the ovule is quite 

 naked, there is no stigma, no style, and the 

 pollen grains find an open way right down to 

 the egg cell. This character is a constant one 

 throughout the whole of the gymnosperms, a 

 name which really means plants with naked 

 seeds. 



Now, a close comparison between a typical 



