Appendix E 423 



as a population, to show graphically the extent of bud variation 

 present. 



EXERCISE 6 



Statistical Study of the Quantity of Grapes from Different Grape 



Vines 

 Use the same general method as in Exercise 4. 



EXERCISE 7 



Study of Variation in Pressed Specimens of Ragweed or Some 

 Plant showing Many Different Types 



Object. Careful study of the large and small variations among 

 different biotypes of ragweed (Ambrosia artemisiifolid) . 



Materials. Specimens of many different types of the above 

 plant or any species of plant which is rich in biotypes. These 

 specimens should be carefully pressed and mounted. (See Figs. 

 108 and 109.) Have each student make detail drawings to show 

 minute differences. 



EXERCISE 8 



Study of Bud Variations and Reversions in Ferns 



Object. To determine the nature and amount of reversion 

 from the parental type, and if possible to find some cause for 

 the same. 



Material. Obtain specimens of the sword fern (Nephrolepis 

 exaltata) and Boston fern (Nephrolepis bostoniensis) and as many 

 of the other ferns named below as possible. 



Study the trueness to type of each variety and any reversions 

 which they may contain. Draw typical specimens. 



The following is the history, according to Cogswell, of some 

 of the fern varieties. This is not a complete list but gives 

 an idea of the origin of a few common horticultural varie- 

 ties. 



