24 Principles of Plant Culture. 



corn, wheat and many other seeds, the seed-case is of 

 such a nature that it absorbs and transmits water read- 

 ily. In certain seeds, however, as of the honey locust, 

 canna, thorn apple, etc., especially if they have been 

 allowed to become dry, the seed-case does not readily 

 transmit water at growing temperatures. Such seeds 

 may lie for weeks, and even months, in tepid water 

 without swelling, but when the water is heated to a 

 certain degree, they swell promptly, a fact often turned 

 to account by nurserymen (36). We cannot always 

 judge by the appearance of a seed-case whether it will 

 transmit water readily or not. 



SECTION II. GERMINATION. 



28. What is Germination? If we place a few viable* 

 grains of Indian corn between the moist cloths of a 

 seed-tester (Fig. 6), cover with the glass and place in a 

 warm room, we shall observe if we examine the corn 

 frequently, that a change, aside from the swelling, will 

 soon take place in at least a part of the grains. The 

 seed-case will be burst by the pressure of a tiny white 

 shoot from beneath. We say that such grains have 

 sprouted or have commmenced to germinate (ger'-mi- 

 nate), i. e., have taken the first visible step toward de- 

 veloping into a plant. 



We have seen that the mature seed contains proto- 

 plasm in its dormant condition (13). At a suitable 

 temperature, the protoplasm, on the absorption of 



the plant. To avoid explaining the technicalities of a complex 

 subject, it seems preferable to adopt a term that will include the 

 various words used in botany to designate the outer coverings 

 of seeds. 



* A viable (vi'-a-ble) seed is one that is capable of germina- 

 tion. Not all seeds are viable (164). 



