THE EMBRYO AND SEEDLING 



135 



the spiny character in young plants, but it is rather 

 uniformly absent in plants more than fifty years old. As 



74 



Figs. 74-76.— Parts of leaves showing character of leaflets: Fig. 74, 



Dioon ediile: leaflets of seedling showing spines near the tip; Fig. 75, 



leaflets of adult plant with no trace of the spiny character; Fig. 76, 

 Dioon spinulosum: spiny leaflets of the adult plant. 



far as this character is concerned an individual might 



begin its career as E. AUensteinii and end it as E. 



coffer. 



