3IO 



ECOLOG K 



hours. The pumpkin seed is the one we have selected for this study. It 

 will be instructive first to examine those which have been germinated in the 



Fig. 404. 



Germinating seed of pumpkin, showing how the heel or " peg " catches on the seed coat 

 to cast it off. 



folds of moist cloth and paper, so that they can readily be observed at all 



stages, without digging them up from the soil. 



587. The root pushes its 



way out from between the 



stout seed coats at the 



smaller end, and then turns 



downward unless prevented 



from so doing by a hard 



surface. After the root is 



1-^cni long, and the two 



halves of the seed coats 



have begun to be pried 



apart, if we look in this rift 



at the junction of the root 



and stem, 



we shall 



see that 



one end 



of the seed coat is caught 



against a heel, or "peg," 



which has grown out from 



the stem for this purpose. 



Now if we examine one 



which is z. little more ,ad- 



vanced, we shall see this 



heel more distinctly, and 



also that the stem (hypo- 



cotyl) is arching out away 



from the seed coats. As 



Fig. 405. 

 Escape of the pumpkin seedling from the seed coats. 



