214 The Flora of the Cam //'</</< 



In East Anglia they would tend to be abmid;inl, eU-where 

 they would be few in numbers, although widely scattered 

 through many districts. 



Such for example would be Cerastitun ///vr//.sv and A mm 

 pratensis. The distribution of the former may be quoted to 

 illustrate this. Its census number in the London (Jatl<xjm>, 

 9th Edition, is 69. Round Cambridge in dry chalk or sand 

 country it is exceedingly abundant, often forming quite a 

 feature in the landscape, yet in Berkshire, Oxfordshire and 

 Hampshire it is not common though scattered, and in 

 Somerset it is confined to two localities, one near Bristol, 

 the other on the Mendips. 



Although it is easy to suppose xerophytic modifications in 

 this association, it is not so easy to prove it. Some plants, like 

 Verbascum pulverulent-urn with its dense downy covering and 

 Avena pratensis with its jointed leaves, are obvious, others, 

 like Antkyllis vulneraria which rolls its leaflets upwards over 

 numerous sunken stomata, and yet possesses a few ordinary 

 stomata on the under surface, are doubtful. 



As to the great mass of our flora it is impossible to 

 make any statement, too often it is a question of position 

 of stomata, thickness of cuticle, &c. which necessitates micro- 

 scopical observation; this has not been done, nor is there time 

 to do it before this paper goes to the press. 



Hairyness has therefore been taken as a test of xerophyhsm, 

 for in any flora the fact whether a plant is glabrous or not can 

 at once be noted without going to the actual specimen. 



All plants mentioned as being hairy or downy in Bentliani 

 and Hooker's Students Flwa were marked off, and those 

 rejected which grew upon damp heavy soils or in water. It 

 may be pointed out here that the term "Xerophytes" includes 

 three groups of plants, salt-loving plants or Haloph 

 plants living in dry well-drained soil, and plants living in badly 

 drained soil where evaporation being rapid upon the surf-ice 

 so cools the underlying soil or water that absorption is very 

 slow. Plants belonging to the second class were taken as 



