lo Introduction to Botany. 



stored up for its use in germination ? How does it differ 

 from the embryo of the Lima bean in this respect ? Com- 

 pare the means of protection possessed by the seed of the 

 castor bean with that of the Lima bean. 



Indian Corn. 



19. Make drawings of the exterior appearance of a 

 grain of Indian corn, from the two points of view which 

 you consider the most important. Scale, x 2. 



20. Remove the skin from a soaked grain, and if any 

 new structures are revealed, draw to the same scale. In 

 this instance and in all grains the wall of the ovary in 

 which the seed is formed constitutes a part of the skin. 



21. Carefully dissect out the central structures from a 

 soaked grain and draw from the two most instructive 

 points of view to the scale, X 3. 



22. With a sharp knife, make cross sections of the inner 

 structures on either side of the center, about halfway 

 toward each apex. Examine with a lens, and draw to a 

 scale large enough to show all that the lens has revealed. 



23. Halve a soaked grain longitudinally through the 

 lesser diameter, making a sliding cut with a sharp knife 

 so as to secure smooth surfaces. If the knife does not 

 pass through the middle of the structures, carefully trim 

 the larger piece until an exactly central section is secured. 

 Draw the cut surface. Scale, x 3. Place a drop of iodine 

 solution on the cut surface, and after a minute draw it 

 off with filter paper. The iodine will color the starchy 

 parts of the seed a deep purple. 



Germinating Indian Corn. 



24. Make drawings of the external appearance of 

 germinating Indian corn in successive stages of develop- 

 ment. Scale, X 1.5. 



