— 354 — 



[Ä.inda]. On the other band, the same writer speaks ^ i of A. densi- 

 ßora [A. albicans mediopida?'] as producing variegated plants both 

 by seeds and suckers. Of the comparably variegated forms of 

 Yucca aloifolia, it has been stated-) that seedlings are green; but 

 V i V i a n d - M o r el 3) speaks of a few variegated seedlings among some 

 fifty green ones, raised from a variegated Yucca. 



These Statements, if accurate, showthat in some cases variegation 

 in these genera is seminally transmissible: if so, it is unsafe to say 

 that the character may not h'e dormant in any or all of the green 

 seedlings of variegated parentage, awaitingdevelopment in themselves 

 or their offspring by favoring environment, like the latent image 

 on a Photographie plate. It is to this extent, only, that environment 

 appears to vi^ork in this class of variations, which in this respect 

 seem comparable with certain fasciations ^). 



Variegated plants in these groups as a rule seem to transmit 

 their characters true to suckers, and this is the common mode of 

 propagating them in gardens. Morren-^) states that the long- 

 established / marginal?] variegation of A. americana is always trans- 

 mitted true in this way. No observations appear to have been recorded 

 on the bulbils of such plants, but the abundant variegated forms 

 of Furcraea Selloa and Agave angnstifolia ought to afford ready 

 evidence on this point in the warm parts of the world. Though 

 the broadly striated and median-banded forms of variegation, which 

 appear to be only extremes of a Single type, seem to interchange 

 when vegetatively propagated, and the latter has even been seen 

 to give origin to entirely greenish-white, white, oryellow suckers toofar 

 etiolated to be capable of independent existence*^), there is as yet 

 no recorded evidence that the marginal and median types of variegation 

 are so interchangeable, and no median variegations have been 

 reported during the forty or fifty years in which Furcraea Selloa 

 niarginafa and Agave picia have been commercially propagated. 



However it may have originated and whatever its unseen 



1) 1. c. 255. 



^) Gard. Chron. n. s. 18: 245: 407. (1882). 



3) Lyon Horticole. 1893. 144. 



^) Cf. Hus, Fep. Mo. Bot. Gard. 17: 149: (1906). 



•^) Bull. Acad. Belg. II. 1«: 234. (1865). 



«) Wein gart, Monatsschr. f. Kakteenkunde. ;>: 30. (1895). — Roland- 

 Gosselin, Rev. Hort. 71: 254. (1899). - The latter writer finds that at least 

 one-eighth of the leaf-surface must be green to enable the plant to live after 

 Separation from the parent plant. 



