154 STUDY OF COMMON PLANTS. 



I. With entire specimens make a careful study of the 

 blue-eyed grass, noting all the points in which it agrees 

 with the Iris or differs from it. 



1. Compare the essential organs as to number, position, 



and structure. 



2. How does the perianth differ from that of the Iris ? 



3. Compare leaves, stem, and roots. 



II. Record concisely the results of your comparative 

 study of the two genera, taking care to bring out the 

 really essential features that indicate their relationship. 



In like manner compare with the two preceding species 

 any other plants of this family that can be procured, 

 as the cultivated Gladiolus or Crocus. Some of the latter 

 open early in the spring, and the study of the Iridacese 

 may begin with them if more convenient. After studying 

 as many representatives of the family as practicable, 

 summarize your observations in a brief synopsis of the 

 characters common to them all. As a subject of special 

 investigation, a comparative study of the arrangements for 

 fertilization in the Iridacese is suggested. 



