TH^ 1>LAN books 



On a work of such colossal scale another 

 point of definiteness can not be overlooked, — 

 the precise location of the various plants 

 under test. For this purpose there are concise 

 memoranda showing where each selected plant 

 is growing. Sometimes it will be a certain 

 direction in so many feet from some certain 

 fixed monument, as a tree, or a fence -post, or 

 the corner of a conservatory, or what not. 

 The plant, when it is finally chosen from 

 among its thousands of fellows, is given a 

 white streamer of cloth to distinguish it, and 

 there are the usual inscribed stakes to 

 identify it, but any of these might be de- 

 stroyed and the plan books contain the 

 definite means for determining just where 

 the plant is growing. When so very many 

 tests are under way at the same time and 

 the aggregate number of the selected plants 

 is so large, it becomes necessary to have pre- 

 cision and definiteness in some indisputable 

 form. 



Now and again, sheets will be found in 

 which the stages of a plant's progress are 

 indicated by large capital letters — A B C, 

 and so on — distributed over the page and serv- 



