THE AMERICAN BOTANIST 57 



(.Til >\>U'inati>l> >< iiiK'tiiHc's make a> nianv as sixteen [jriinary 

 tlivisions but this ackls nothing of interest to the beginner. 

 The usual (hxisioiiot the Spermatophxtes is into the Gvmno- 

 spernis ur cone-bearing trees and the .Angiospernis or true 

 flowering phuits. In other systems of classification these are 

 occasionally given ecpial rank as primary divisions and known 

 as Strobilophyta and Anthophyta, res[)ectively. Each of the 

 main dixisions of plants have entire volumes devoted to cata- 

 loguing their species, but books on the flowering plants are 

 naturally more numerous tlian all the others put together. 



VITALITY OF CANNA SEEDS 



By J. Ford Skmpers 



np HOSE who have planted tile seeds of the garden canna 

 ■'■ have doubtless noticed the hard, shell-like covering ap- 

 parently hermetically enveloping the seed. Years ago when 

 the plant was more conspicuous for its foliage than for its 

 blossoms it was sometimes known, as shot-plant, a name sug- 

 gested of course by the hard round seeds it bore. 



Gardeners are accustomed to resort to some mechanical 

 means of puncturing this impervious outer covering that the 

 elements necessary to germination may be more readily ad- 

 mitted. This is sometimes accomplished by cutting through 

 the outer covering with a file or emery wdieel, but to be more 

 practical the seeds may be placed in a test tube or some simi- 

 lar container and covered with boiling w^ater. A pronounc- 

 ed popping sound ff)llows which indicates the rupturing of 

 the shell like covering. The l)rief application of high tempa- 

 ture does not appear to affect the vitality of the seeds, but 

 occasionally there will be a few tiiat resist its action. It is 



