346 Campbell . — Studies on the Araceae , ///. 
plants the species of Peperomia , where there are usually sixteen nuclei. 
The multiple nuclear fusions also find a parallel in Peperomia . 
The great difficulty in finding healthy pollen-grains, and the rarity 
of fertilization stages, makes it probable that some of the conditions 
enumerated were pathological, so that it will not be safe to lay too much 
stress on them. The fact that perfect seed was formed in many cases, 
however, and the perfectly healthy appearance of the cells, together with 
the complete absence of the ordinary type of embryo-sac, is a strong 
indication that the plants real Jy differ normally a good deal from the 
usual type. 
In all the species investigated the endosperm is septate from the first, 
and soon completely fills the embryo-sac. The basipetal growth as shown 
in A nthurium and Spathicarpa is probably characteristic, but there are 
doubtless some modifications of this. The separation of the endosperm 
into two marked regions (basal and apical) characterized by different cell 
contents is not uncommon, and the difficulty of distinguishing the basal 
endosperm from the antipodals is a strong argument for considering both 
of these as really gametophytic tissue, the antipodals being merely 
specialized prothallial cells. 
According to Engler 1 the presence or absence of the endosperm in 
the ripe seed is of great importance systematically, as the natural groups 
show great constancy in this respect. The great development of the 
chalazal portion of the ovule, and relatively small embryo-sac in such 
forms as Aglaonema and Lysichiton , may be compared to the development 
of the perisperm in the Piperaceae. The suggestion has already been made 
by the writer 2 that the resemblances in general habit, as well as the 
distribution of the vascular bundles in Peperomia and the Araceae, might 
indicate a remote relationship between them ; the presence in the latter 
of nucellar tissue, which might be compared to the perisperm of the 
Piperaceae, might be cited as further evidence of a possible relationship. 
We may conclude, then, that the Araceae are really a primitive family 
of Monocotyledons, the forms with unisexual flowers being less specialized 
than those with hermaphrodite flowers. The not infrequent occurrence 
of a multicellular archesporium and the tendency to great variability in 
the number of the nuclei of the embryo-sac all point to such a conclusion. 
The relationship of the Araceae to other low Monocotyledons has 
been recognized, but their nearer affinities are not very certain. The 
possibility of a connexion with some of the lower Dicotyledons through 
forms like Peperomia may fairly be considered worthy of consideration. 
1 Loc. cit., p. 107. 
2 The Embryo-sac of Peperomia. Ann. of Bot., March, 1901. 
