HALF-HOURS IN THE GREEN LANE*. 



It is the form and arrangement of these that con- 

 -stitntes what botanists call areolation. It is of 

 great importance in the diagnosis of species, inas- 

 much as it varies in different genera, and frequently 

 even in different species of the same genus, as may 

 be seen in Figs. 228, 229. The cells often contain 

 grannies of the green substance peculiar to all 

 plants, called chlorophyl. Keference has also been 

 made to the reproductive organs, which are of two 



Fig. 230. Fig. 231. 



Three Archegonia and Para- 

 physes of Dryum. 



Two Antheridi;i and Para- 

 physes of Polytrichum. 



kinds, male and female. The occurrence of these is 

 pretty much like that of the male and female organs 

 Df true flower-bearing plants. Sometimes they are 

 combined on the same plant; at others they are 

 separate, but on the same plant; and frequently 

 they are separate, on different plants. The male 

 organs are usually surrounded by a circle of small 

 leaves called the perigonia. The male organs 

 are called antheridia (Fig. 231) and they eeeiu 



