the leaves from the air. As these substances are subjected in Vlew 

 the leaves to the combined action of light and chlorophyll, the 

 formation of the carbohydrates takes place. Less is known 

 about the formation of proteids^ but it is believed that they are 

 formed in the leaves much in the same way as the carbohy- 

 drates, although light does not act so directly in their produc- 

 tion. The proteids are produced in much smaller quantities 

 than carbohydrates, but they are nevertheless of greatest 

 importance to the life of the plant. 



DESCRIPTION OF THE PLANT. 



GERMINATION. 



The vegetative life of the plant begins with the germina- 

 tion of the seed, and for this process moisture, air, and the 

 proper temperature, all operative at the same time, are re- 

 quired. The parts of the wheat kernel of prime importance 

 n germination are the embryo, or germ, which develops to 

 form the young plant, and the endosperm, or starchy reserve 

 material, which serves as the source of food for the embryo 

 in the first stages of growth. The embryo is composed of a 

 vegetative portion, or that part containing in minute form 

 the leaves and roots of the new plant, and the scutellum, 

 which during germination brings the starch or flour of the 

 endosperm into solution and transfers it to the growing parts. 



The first step in germination is the absorption of water, of 

 which the wheat kernel takes up from five to six times its own 

 weight. The outer layers of the kernel are ruptured and the 

 vegetative portion of the embryo begins to develop its minute 

 leaves and roots by means of the food derived from the endo- 

 sperm, until finally parts of the young plant appear above 

 the ground and become green, thus showing that chlorophyll 

 or leaf -green has been formed. The chlorophyll is a sub- 

 stance playing an important part in the formation of new 

 organic matter in the plant. At this stage the roots begin to 

 take up inorganic matter held in solution in the soil water 

 which they absorb, and under the action of air and light the 

 young plant changes this inorganic matter into the organic 

 matter of plant tissue. All the nutritive material in the en- . 

 dosperm has now been consumed. The process of germina- 

 tion is completed and the plant is self-supporting. 



THE ROOTS. 



The germinating kernel of wheat produces a whorl of sev- 

 eral small temporary roots, which are followed by a set of 

 permanent roots thrown out from the crown, a joint or group 



