142 LABORATORY LESSONS IN GENERAL SCIENCE 



5. What advantage is there (if any) in having the ker- 

 nels wedge-shaped? State if there is any dent in the large 

 end of the kernel. What differences are there in the sides 

 of a kernel ? With a knife remove the thin outer coating 

 of a kernel (its hull). Note where the color of the kernel 

 seems to be lodged. At what place in the hull is a hole 

 found? What is its probable purpose? 



6. Examine some kernels that have been in water for two 

 or three days, and away from the light. What change has 

 occurred in the size of the kernel, and of the groove in its 

 side? Having removed the hulls, cut some of the kernels 

 lengthwise along the groove, and others lengthwise but at 

 right angles to it. Observe the little embryo in each case. 

 The large portion of the kernel surrounding the embryo is 

 the endosperm. 



7. Put several of the soaked kernels between blotting 

 papers kept moist in a warm room for several days; Ex- 

 amine the embryo, and infer what it is likely to become. 

 Distinguish between its plumule and its radicle (root). Dis- 

 tinguish any parts of the plumule, and of the root. Observe 

 any hairlike rootlets, and tell where they are. The change 

 which has taken place in the kernels is called germination. 

 After corn is planted, to what extent can conditions for 

 germination be controlled ? About how early in the Spring 

 is it safe to plant corn in your section of country ? 



8. Fill a glass fruit jar with mellow soil that is somewhat 

 moist (but not water-soaked). Push down into the soil 

 next the sides of the jar where they can be seen several 

 kernels that have been soaked for three days. Have them 

 at different depths below surface. Keep the soil just moist, 



