ORGANS OF VEGETATION 



145 



has been carefully pollinated it is necessary to cover the blossom 

 with a thin bag to prevent the access of stray pollen. Finally, as 

 a last precaution the fruit itself should be bagged to protect it 

 against ravages of insects and birds. Each flower should be 

 carefully tagged so that no mistake may be made in recording 

 our results. 



The seeds are the final product of the flower and as they approach 

 maturity the outer portions of the flower perish and fall away. 

 In general, we may say that every seed consists of an outer coat, 

 an inner coat, and a kernel. The outer coat is often hard, while 

 the inner coat is always thin and delicate. 



The kernel is the body of the seed within the seed coats and it 

 contains the embryo. Sometimes the embryo constitutes the 

 principal part of the kernel and sometimes a 

 large part of it consists of albumin. 



The embryo is the rudimentary plantlet, and 

 its essential parts are the radicle and the cotyle- 

 dons. The cotyledons are the original pair of 

 leaves or seed leaves, and the initial stem on 

 which they are supported is called the radicle. 

 Interesting results may be had by germinating or 

 sprouting some butter beans and noting the 

 development of the embryo from time to time. 

 Fairly good seed testers for germinating seed may 

 be made by inverting saucers in soup plates or 

 inverting small pie pans within other pie pans 

 just a little larger. If the first plan is used, 

 cover the saucers with moist blotting paper or cheesecloth and 

 keep the seed damp until the sprouting is complete. Count the 

 seeds and note the percentage that germinate, also note the time 

 required for germination in different seeds. In high schools and 

 colleges where the pupil is supplied with good equipment experi- 

 ments should be conducted under different temperatures with a 

 view to ascertaining at what temperature seed will germinate the 

 most rapidly. Small sponges placed in a dish or glass of water 

 may also be used as germinators when other materials are not 

 available. In fitting up a seed tester by the first plan it is best 

 to place a moistened cloth above the seed as well as below the 



PRAC. AGRICUL. 10 



Bean seedling. 



