NUTRITION 



85 



such as the various oils derived from plants. Fat occurs 

 in the solid form in the cocoanut. In the tallow-tree 

 (Sapium sehiferum) it is so abundant, as a waxy coating 

 on the seeds, that it is used in eastern Asia for making 

 candles. Fats commonly occur in droplets in the proto- 

 plasm, or as an emulsion in the cell-sap, but the place 



Fig 62 —Portion of a cross-section of a grain of Indian corn {Zea 

 Mays) G.E, glandular epithelium of the scutellum which secretes dias- 

 tase; G, a simple racemose gland in the tissue of the scutellum; D, duct of 

 the latter, emptying into the starchy endosperm surrounding the embryo. 



and method of their formation have never been clearly 

 determined. 



85. Digestion.— We have learned above (paragraph 42) 

 that substances can enter a plant only in solution. It is 

 also true that substances, even when inside the cell, can- 

 not be utilized as food by the plant unless they are in 

 solution. In order that the protoplasm can be nourished, 



