Study of an Endogen. 



109 



you have not already made drawings of the embryo do so 

 now. Look again at the figure in Exercise 42. 



Bring for the next exercise an entire plant with the 



flower parts in 

 threes. 



EXERCISE 57. 



Study of an 

 Endogen Plants 

 which have their 

 floral organs in 

 sets divisible by 

 three usually have 

 leaves with paral- 

 lel veins; stems 

 without a distinct 

 pith; woody fibers 

 not forming a 

 cylinder, and seeds 

 in which the embryos have not 

 two or more cotyledons. These 

 are the most obvious character- 

 istics tfendogens. 



Study one of the flowers of your 

 plant. Draw a plan of it and make 



drawings of itS OrganS. DraW a SeC- 

 



tion of the stem; a leaf or part of it; 

 the bulb, corm, root stock, or root. 



Fig. 84. 

 Reduced 



Zygadenus (an endogen). 

 from a drawing by Helen 



