666 Campbell . — Studies on the A raceae. 
Nearly all the Araceae that have been studied show certain 
anomalies in the character of the embryo-sac, and this makes 
it all the more desirable that further investigations should be 
made upon this interesting family. Both of the species 
especially treated in the present paper show more or less 
marked deviations from the ordinary angiospermous type. It 
is hoped that further study of other genera of the Araceae 
may not only add to our knowledge of this family, but may 
also throw light upon the character and origin of the embryo- 
sac of the lower Monocotyledons. 
Among other forms collected in Jamaica in 1897, was a 
species of Aglaonema , probably A. commutatum , cultivated 
under the name Dieffenbachia Aglaonema , which showed some 
puzzling abnormalities ; but the material was too incomplete 
to make a thorough study of these possible. What was 
apparently the same thing was found flowering freely at Kew, 
and a good supply was secured which served for the basis of 
the work now recorded. Much the same peculiarities of the 
embryo-sac noted in the Jamaican specimens were found, and 
a fairly complete study was made of the species. 
The other form to which special attention has been given 
was Spathicarpa sagittaefolia , which was flowering and fruiting 
very freely in the Kew greenhouses. 
Owing to the large amount of mucilaginous matter secreted 
by the ovules in many Araceae, they are especially difficult 
to fix properly, and even with the greatest precautions much 
of the material was very unsatisfactory. On the whole, the 
best results were obtained by the use of a concentrated alco- 
holic solution of corrosive sublimate. Aqueous fixing fluids 
were useless in most cases. Some good results were also 
obtained by the use of alcohol, to which ten per cent, of acetic 
acid was added. This was not specially satisfactory for fixing 
nuclei, but otherwise often gave very good results. Fleming’s 
triple stain was used with success in some cases, but very 
good preparations were also made by staining with alcoholic 
Bismarck-brown and aniline-safranin. 
Most of the Araceae that have been examined show various 
