II4 SEEDS AND SEEDLINGS 



stem as you did in the bean. Reverse the position of a 

 number of seedlings, so that the hypocotyl shall point 

 upward and the plumule downward, and watch the effect 

 upon their growth. After a few days reverse them again 

 and note the effect. In sections where cotton seed can not 

 be obtained, maple, ash, morning-glory, or squash, pumpkin, 

 etc., may be substituted. 



PRACTICAL QUESTIONS 



1 . Do the cotyledons, as a general thing, resemble the mature leaves 

 of the same plants? 



2. Try to account for the difference, if you observe any ; could con- 

 venience of packing in the seed coats, for instance, have anything to 

 do with it? 



3. If seeds are planted in the ground in a number of different posi- 

 tions, will there be any difference in the position of the seedlings as 

 they appear above ground? 



4. Of what advantage to the farmer is this tendency of seedlings to 

 right themselves? 



GROWTH 



MATERIAL. A flower pot suspended by a wire, some bulbs, and 

 several well-developed seedlings to experiment with. 



155. What Growth Is. With the seedling begins the 

 growth of the plant. Most people understand by this 

 word, mere increase in size ; but growth is something more 

 than this. It involves a change of form, usually, but not 

 necessarily, accompanied by increase in bulk. Mere me- 

 chanical change is not growth, as when we bend or stretch 

 an organ by force, though if it can be kept in the altered 

 position till such position becomes permanent, or as we say 

 in common speech, " till it grows that way," the change 

 may become growth. To constitute true growth, the 

 change of form must be permanent, and brought about, 

 or maintained by forces within the plant itself. 



Remove the scales from a white-lily bulb, weigh them, and 

 lay them in a warm, not too damp, place, away from light. 



