248 



STUDY OF FRUITS AND SEEDS. 



PLUMULE 



Keep a record (1) of the aspect of each type as it 

 appears above ground, the number of cotyledons, size, 

 etc. ; (2) of the order of appearance above ground of the 

 different seedling types ; (3) of the average time taken to 

 germinate by each type under the heat, etc., conditions of 

 the experiment. Repeat the ex- 

 periment, varying the conditions 

 as regards heat, depth below sur- 

 face, etc. In one mixed sowing a 

 fixed number of each kind might 

 be used and the whole thing left 

 to flower, or seed. The numbers 

 of each kind successful in pro- 

 ducing seed should be counted 

 and tabulated. In such experi- 

 ments as these the teacher will be 

 able to demonstrate the effect on 

 various types of the struggle for 

 light and room, of the advantages 

 of particular habits of growth, and 

 so on. 



Particular note should be made 

 of what comes above ground as 

 distinct from what is seen to grow 

 afterwards. Examples of the 

 different kind of seedlings should 

 be carefully removed from the soil 

 and drawings made. It will not 

 be difficult to indicate that in 

 general there emerge from seeds 

 under normal conditions a root 

 (radicle), a shoot (plumule), seed- 

 leaf or leaves (cotyledons). 



Individual seeds may now be 

 appropriately examined with a 

 view to discovering how much of 

 this is already formed in the seed. Beans, being of con- 

 veniently large size, are generally used for this purpose. 

 They may be opened after soaking for some time, when 

 the radicle and plumule may be demonstrated, and also 



---RADICLE 



Fig. 127. Young Seedling of 

 Maize in longitudinal section. 



