ONAGRARIE^E 



63 



In its final form (fig. 108) the new portion is both broader 

 and longer than the true cotyledon, and differs from it not 

 only in the crenations, but in the possession of a more con- 

 spicuous midrib and rather stiff hairs. Not only is this basal 

 portion interesting in its mode of development, but also 

 from its similarity to the subsequent leaves. In fact, as 

 fig. 108 shows, it may be said that we have a compound 

 structure formed of a leaf at the base, terminated by the 

 cotyledon. 



If, indeed, this spe- 

 cies stood alone, we 

 might regard the re- 

 semblance as acci- 

 dental ; but we find a 

 very similar growth in 

 other allied species. 



In Clarkia pulchella 

 (fig. 109) the cotyle- 

 dons immediately after 

 germination closely re- 

 semble those of Eucha- 

 ridium grandiflorurn 

 (fig. 106). In a short 

 time they become 

 broadly ovate, emar- 



ginate, Suddenly nar- FIG. m. Clarkia pulcheUa. Two-thirds nat. size. 



rowed, and rounded 



at the base. In this case there is no great change of form ; 

 but while the margin of the original cotyledon is glabrous, 

 that of the new growth and of the true leaves (fig. 109) is 

 finely ciliate. 



In (Enothera stricta the cotyledons immediately after 

 germination are oblong, obtuse, slightly auricled at the base, 

 otherwise entire, sessile, thinly glandular-pubescent on the 

 upper surface, and ciliate. By continued intercalary growth 

 at the base they eventually become (fig. 110) spathulate, ob- 

 ovate or oblong-obovate, obtuse, with a tooth on each side, 

 indicating the point of union of the original cotyledon and 

 the new growth ; the lower part with a distinct midrib 



