EEJUVENESCENCE IN NATURE. 73 



mostly by three more euphyllary leaves (unfolded in the next 

 spring), the first of which is seated either on the creeping 

 portion of the stem, or raised but a little above the 

 ground on the lowest part of the erect euphyllary-leaved 

 stem, and it is by far the largest of all, for it equals or 

 even exceeds in height the entire shoot, attaining a length 

 of a foot to a foot and a half. The two following, 

 situated high up on the stem, are, the first 9 to 6 inches, 

 the second 4 to 3 inches long. The hypsophyllary leaves 

 succeeding upon the inflorescence are totally suppressed 

 in this plant. The exaltation of the leaf-formation ex- 

 pressed in the euphyllaryformation appears most strikingly 

 in the cases where this is represented by a single euphyl- 

 lary leaf, which is then mostly of remarkably large size. 

 Thus in Epimedium alpinum* where the tolerably numer- 

 ous subterraneous cataphyllary leaves, from 1 to 5 lines 

 long, are ordinarily followed by a single twice or thrice 

 divided euphyllary leaf about a foot long, after which the 

 metamorphosis springs over suddenly to the small and 

 numerous hypsophyllary leaves, the length of which 

 amounts at most to 1 line, and sinks to id of a line. There 

 is somewhat of a deviation from the usual position of the 

 maximum of development in length of the leaves, in the 

 rare cases where this occurs at the end or the beginning 

 of the euphyllary formation, instead of in the middle. 

 We see the first case in Heliconia cannoidea,^ in which 

 the decrease of length commences in the hypsophyllary 

 formation ; the last in Pceonia and Actcea. The bane-berry 

 {Adeea spicatd) presents on the subterraneous stock several 

 short-sheathed cataphyllary leaves, increasing in length 

 from 1 to 3 lines ; to these succeed, upon the erect stem, 

 mostly three euphyllary leaves ; the lowest, largest, very 

 decomposed, is about 1 foot long, while the third, 



* Other examples of one-leaved euphyllary formation are furnished by 

 Malaxis monophylla, and very many exotic Orcliidacese ; also by many 

 Aroidese, e.g.. Arum echinalum, (Wall. pi. as. rar. t. cxxxvi) ; by Gesneriacese, 

 as in Platystemma violoides, (Wall. 1. c., t. cli) ; by Sanguinaria ; and lastly 

 by many Cyperacea;, as for example, Scirpus mucronatus. 



t Richard, ' Comment, de Musac.,' t. ix. 



