1 6 Humphrey .— The Development of the 
parietal layer, this usually becomes disintegrated without the 
production of cell-walls, as in the Vicieae, LimnantJiemum , &c. 
The persistence of the single layer and its acquirement of the 
character of an aleurone-layer strengthens the probability 
indicated by Guignard’s results, that it has a special physio- 
logical significance. This seems especially probable in the 
light of the recent researches of Griiss (’95), confirmatory 
of Haberland’s earlier view (’90) of the aleurone-layer as 
a diastase-producing tissue. 
In comparing the seed-development of Canna with that of 
other Scitamineae, we may first examine those nearest to it 
in floral structure, the 
Marantaceae. 
If any suggestions as to the origin of the peculiar develop- 
mental history of the seed of Canna are to be found, one 
would expect them from Marantaceae. Material of even the 
chief stages in the development of the seeds of these plants is 
very difficult to procure ; and, in spite of many efforts, I have 
not succeeded in obtaining a complete series of any member 
of the family. Of most forms seen I have been able to 
examine only the ovules at about the time of flowering, or 
the ripe seeds. The discussion of the family must, therefore, 
be very incomplete. 
The ovules are very uniform in structure and position 
throughout the family. Their position has already been 
described. Each ovule shows from an early stage (Fig. 25 ) 
a greater development of the outer than of the inner side of 
the nucellus and of the corresponding parts of the integu- 
ments ; so that the nucellus becomes bent around against the 
funiculus, as in an anatropous ovule, while its morphological 
base, at the chalaza, is not opposite the micropyle, but at one 
side (ch. , Fig. 2 6 ). Thus the ovule is neither typically ana- 
tropous nor campylotropous. Its attachment is by a short 
and fleshy portion into which the vascular bundle passes from 
below, and which must be regarded as a much thickened 
funiculus. The ovules of members of the genera Mar ant a, 
