THE EMBRYOGENY OF SOME CUBAN NYMPHAEACEAE. 
MELVILLE THURSTON CooK. 
(WITH PLATES XVI-XVIIL.) 
THE taxonomic position of the Nymphaeaceae has always been 
somewhat doubtful. The anatomy of these plants is more nearly 
_ that of the monocotyledons, while the venation of the leaves would 
indicate that they are dicotyledons. A few years ago researches in 
this family were stimulated by Lyon’s studies (17, 18) on the embry- 
ogeny of Nelumbo, in which he came to the conclusion that they should 
be classified among the monocotyledonous families in the series 
Helobiae. Lyon’s views were strengthened by my own paper on 
the embryogeny of Castalia odorata and Nymphaea advena (7), by 
SCHAFFNER’S paper on morphological peculiarities of the Nymphae- 
aceae and Helobiae (26), and by Yorx’s embryological studies on 
Nelumbo (28). But Conarp (5, 6) in his studies in this same family 
took exceptions to this view, and holds to the idea that they should 
be classified among the dicotyledons. More recently, MoTTIER (20) 
has declared his belief that they are anomalous dicotyledons. How- 
ever, he does not claim to have made any study of the Nymphaeaceae, 
but confines his studies to well recognized dicotyledonous species. 
Immediately following Lyon’s paper (18) on the embryogeny of 
Nelumbo, CAMPBELL (4) raised the question as to whether other 
genera of the Nymphaeaceae might not also be monocotyledonous, 
and called attention to the fact that the structure of the flowers and 
character and arrangement of the vascular bundles in Cabomba and 
Brasenia were very similar to some of the Alismales; also “ that the 
form of the leaves is often very suggestive of the sagittate leaves of 
Alisma or Sagittaria.”’ 
In consideration of the differences of opinion indicated above the 
writer accepted an opportunity to make a study of certain tropical 
species, hoping that additional light might be thrown on this very 
interesting family. : 
SCHAFFNER (26) called attention to the fact that it is in reality 
much easier to read monocotyledonous than dicotyledonous charac- 
Botanical Gazette, vol. 42] (376 
