534 Mutations 



spects. The stems are robust, often with twice 

 the diameter of lamarckiana throughout. The 

 internodes are shorter, and the leaves more 

 numerous, covering the stems with a denser 

 foliage. This shortness of the internodes ex- 

 tends itself to the spike, and for this reason the 

 flowers and fruits grow closer together than on 

 the parent-plant. Hence the crown of bright 

 flowers, opening each evening, is more dense 

 and more strikingly brilliant, so much the more 

 so as the individual flowers are markedly larger 

 than those of the parents. In connection with 

 these characters, the flower-buds are seen to be 

 much stouter than those of lamarckiana. The 

 fruits attain only half the normal size, but are 

 broader and contain fewer, but larger seeds. 



The rubrinervis is in many respects a coun- 

 terpart to the gigaSj but its stature is more 

 slender. The spikes and flowers are those of 

 the lamarckiana, but the bracts are narrower. 

 Red veins and red streaks on the fruits afford 

 a striking differentiating mark, though they are 

 not absolutely lacking in the parent-species. 

 A red hue may be seen on the calyx, and even 

 the yellow color of the petals is somewhat deep- 

 ened in the same way. Young plants are often 

 marked by the pale red tinge of the mid-veins, 

 but in adult rosettes, or from lack of sunshine, 

 this hue is often very faint. 



