22 Campbell.—Studies on the Araceae . 
Araceae. This condition is now known in a number of other 
low Monocotyledons, especially the Grasses, and is also a 
regular phenomenon in Sparganium. It is highly probable 
that further research will reveal a similar condition in other 
low Monocotyledons. 
The embryo resembles most nearly that of the Grasses and 
Sparganium , like these being quite destitute of a suspensor, 
and having the cotyledon largely developed. However, as 
the absence of the suspensor is obviously associated with the 
early development of the endosperm, it may be that this 
does not imply a relationship. If, however, these lower 
Monocotyledons have been derived from Fern-like ancestors 
similar to Isoetes , we should not expect to find a suspensor 
developed in them. The lateral development of the primary 
root, also, in such forms as Lysichiton and Pistia , is suggestive 
of the embryo of Isoetes. 
In connexion with this preliminary study of the Araceae, 
which it is hoped may soon be materially added to, attention 
was called, while collecting in Jamaica, to certain remarkable 
similarities in habit between them and the Piperaceae. Both 
in the form of the leaves and inflorescence, as well as in 
certain anatomical characters, e. g. the distribution of the 
vascular bundles in the stem of Peperomia , there are very 
curious parallelisms. The structure of the flower and position 
of the ovule are also similar. That these really indicate any 
relationship between the two orders, it would be rash to 
assume; but the possibility of such a connexion may very 
well be considered. So far as I am aware, no careful embryo- 
logical study has been made of the Piperaceae, and it 
will be necessary to do this before it is safe to draw 
conclusions. 
