EXERCISE 55 (Continued) 



might burs have been carried in former times by such animals 

 as the deer and buffalo ? 



Compare wind-carried seeds and animal-carried seeds of the 

 type of the burs with regard to the following points: 



1. Which sort of equipment is more sure to secure the dis- 

 persal of almost all the seeds on the plant ? 



2. Which sort of equipment is likely to secure the carrying 

 of at least a few seeds to the greatest distance ? 



How do you account for the fact that strange weeds are 

 often found in the vicinity of wool-cleaning establishments ? 



References 



BERGEN and CALDWELL. Practical Botany, pp. 146-155. 

 BERGEN and CALDWELL. Introduction to Botany, pp. 166-171. 



[70] 



