FUNDAMENTAL PRINCIPLES OF PLANT GROWTH. 29 



Class II. Vine fruit culture. 

 Sub-class 



I. Vitieultural fruits: Grape. 

 II. Passifloraceous fruits: Granadilla. 

 Class III. Small fruit culture. 

 Sub-class 



I. Bush fruits: 



Group (a) Rubaceous fruits: Raspberry, blackberry. 



(b) Ribaceous fruits: Currants and goose- 



berries. 



(c) Miscellaneous fruits: Juneberry, buffalo- 



berry. 

 II. Strawberry culture: Strawberry. 

 III. Cranberry culture: Common cranberry. 

 Class IV. Non-woody or herb-like fruits. 

 Sub-class 



I. Musaceous fruits: Banana. 

 II. Pineapple. 

 III. Cactaceous fruits: Prickly pear. 



It has been estimated that there are more than ten thou- 

 sand varieties of our commonly cultivated fruits in America. 

 In order to study these satisfactorily some method must be 

 found to classify them. This matter will be found worked out 

 In the various books on systematic pomology. Botanists have 

 found it convenient to group plants under the head of class, or- 

 der, genus, species, varieties. The same classification, of course, 

 applies to the larger groups in horticulture; but the horticultur- 

 ist has gone farther than the botanist with his classification 

 and has divided his plants into varieties. 



A variety is made up of a group of individuals which differ 

 from the rest of its species in certain recognizable particulars 

 which are transmitted from generation to generation without 

 material modification. The horticulturist makes into groups 

 more or less definite the varieties having certain important 

 traits in common, as, for instance, when he groups certain va- 

 rieties of vegetables or fruits together. New varieties of fruits 

 ar-e being continually offered by the trade, and, although not 

 one in ten of those sent out is as good as those commonly 

 grown, yet from time to time marked improvement is made. 



QUESTIONS— CHAPTER li. 



1. What Is the root system of plants made up of? 



2. Of what value are these parts to the plant? 



3. What is meant by "collar or crown?" 



4. Why does this portion of the tree need protection? 



5. When are plants annuals? biennials? perennials? 



