1904] SARGANT: EVOLUTION OF MONOCOTYLEDONS 33! 
several monocotyledons, including the liliaceous climber Gloriosa 
superba? In this species he finds a well-marked cambium within 
the bundles of the second-year tuber and of all succeeding tubers. 
Secondary elements are added to the xylem and phloem of each 
bundle by its cambium, which is active throughout the two sea- 
sons during which the tuber lasts. Moreover, the bundles in the 
climbing stem of the seedling possess a cambium, though the 
elements which it contributes to the xylem and phloem soon 
lose their radial arrangement by further growth. M. Quéva 
comes to the following conclusion: ‘La persistance de la zone 
cambiale dans certains faisceaux des Monocotylédonées prouve 
qu'il est logique de considérer ces plantes comme dérivant de 
Dicotylédonées inférieures par extinction précoce de la zone 
cambiale et par augmentation du nombre des faisceaux de la 
trace foliaire” (/. c., p. 147). 
It will be remembered that Miss Anderssohn in 1888 described 
acambium in the bundles of the young stem of several mono- 
cotyledonous seedlings.*° 
Professor Jeffrey has recently expressed his phylogenetic 
conclusions without reserve: ‘‘In the present state of our 
knowledge we are apparently justified in considering the mono- 
cotyledons to be a modern, strictly monophyletic, and specialized 
group, derived from dicotyledons or their parent stock, possibly 
by adaptation in the first instance to an amphibious mode of 
life,”’"* 
The evidence on which this view is based is the comparison 
of the mature stem anatomy with that of the seedling in what 
may be called the third period of its life. The first includes all 
the time during which the embryo is completely inclosed by the 
Ovule or seed. The second period begins with germination, and 
while it lasts the seedling consists mainly of cotyledon, hypo- 
cotyl, and primary root. The young stem bud is present, but is 
*QuEva, C., Contributions a l’anatomie des monocotylédonées. Mem. de l’Uni- 
versité de Lille, 
© ANDERSSOHN, S., Ueber d. Entwickel. d. primaren Gefassbiindelstrange d. Mono- 
kotylen, Bihang till K, Sy. Vet. Akad. Handl. 12: 188 (Bot. Centralbl, 38:—. 1889). 
* COULTER and CHAMBERLAIN, Morphology of Angiosperms 316. 1903. 
