48 Dr. J. C. Draper on Groiotli or 



time with which the stractures were evolved in each plant. 

 It also indicates for each plant an equality in the number of 

 periods of evolution, viz. 6, notwithstanding the difference in 

 the weights of the seeds, and suggests that the power of | 

 evolution of structure in seedlings resides in the germ alone. 



The character of the evolution in the six periods shows a I 

 steady improvement or progression. 



In the first, the growth consists of the formation close to the 

 stem of two partially developed pale yellow leaves. 



The second period is similar to the first, except that the 

 leaves are a little larger. 



The third presents a pair of small yellow leaves close to the 

 main stem, from between which a lateral stem or twig about 

 one inch long projects, and bears at its extremity a second pair 

 of imperfectly developed yellow leaves, from between whicli a 

 small tendril about a sixteenth of an inch long is given off. 



The fourth resembles the third, the lateral twig being longer, 

 and the tendi'il three times as long as in the third. 



The fifth is like the fourth, except that the tendril bifurcates. 



The sixth is similar to the fifth, except that the tendril 

 trifurcates. 



Stem, leaves, twigs, tendrils of various degrees of complexity, 

 all are evolved by the force preexisting in the germ without 

 the assistance of light. 



Evolution of striLcture in the light. — 



Table 11.^- Seedlings grown in the light. 



E P Q- IT 



Weight of seed.... 288. 426. 462. 544. 



Period 1 6th day. . . 6th day. 



„ 2 7th day. 7th „ 7th day. 7th „ 



„ 3 8th „ 8th „ 8th „ 9th „ 



„ 4 12th „ 9th „ 10th „ 10th „ 



„ 5 15th „ 11th „ 14th „ 12th „ 



„ 6 13th „ . . 14th „ 



Table II. was obtained in the same manner as Table I., the 

 columns representing the days on which lateral growths and 

 leaves appeared. Though there is not the same uniformity as 

 in Table I., the periods are identical in both as regards the 

 visible character of the evolution. Nothing appears in the 

 second that did not preexist in the first ; and in the case of the 

 seeds E and G the evolution is even deficient as regards the 

 first and the sixth periods. 



While the general character of the evolution in both series 

 is similar, certain minor differences exist. In Table II. the 



