Mutations 65 



parent species. The stems are unbranched and very 

 brittle. CE. nanella is frequently produced as a mutation 

 and is absolutely constant (Figs. 17 and 19). 



Group II, progressive elementary species, possessing new 

 characters : 



CE. gigas is a giant form which is much larger in every 

 respect than its parent, except in height. The stems are 

 much larger ; internodes are shorter and the leaves more 

 numerous than the parent species (CE. Lamarkiana). 

 The flower-buds are large and closely crowded on the 

 spike, and when the flowers open, they make a beautiful 

 appearance (Fig. 20) . 



CE. rubrinervis is characterized by the red veins and red 

 streaks on the fruits. This plant is as tall as CE. gigas, 

 but a little more slender. A feature of this type is the 

 brittleness of the leaves and stems, especially in the annual 

 individuals, of which many are found. 



Many of these mutants may be recognized before the 

 adult stage has been reached, for example, at about the 

 age of two months. The leaves of CE. gigas are broad, of a 

 deep green, the blade sharply cut off from the stalk, all 

 of the rosettes becoming stout and crowded with leaves. 

 In CE. rubrinervis, on the contrary, the leaves are thin, 

 of a paler green, and with a silvery white surface; the 

 blades are in the form of an ellipse, acute at the apex, 

 and gradually narrowing into the petiole. 



Both of these species are quite constant and do not 

 revert to CE. Lamarkiana. However, other mutants have 

 sprung from these two species, especially from rubrinervis, 

 which is produced in greater numbers from Lamarkiana 

 than is gigas. 

 F 



