ai aa 
PREFACE. xxi 
do arenaria and carex arenaria serve in Europe, and 
which might therefore be useful in binding artificial 
embankments 
Gymnospermæ.—The pitted tissue is I believe not 
peculiar to Coniferæ, it occurs in Bucklandiæ and 
Sedgewikia and probably in all other Hamamelidie. 
Deb. Mookh, Feb. 29th, 1836. 
Mr. Solly tells me that coniferous punctuation are 
likewise said to exist in Winteracee. June 29th, 1836. 
Cycadee.—The trunk is in Cycas circinalis generally 
dichotomously branched. The same occurs in the 
Gowahatty species which is probably distinct. The 
second integument of the ovule is united to the 
outer, and so is the lower half of the nucleus to the 
corresponding portion of this. The margins of the 
foramen is callous and lucid: but no change, is effected 
by it on the pollen, which finds its way unchanged 
into a canal existing in the apex of the nucleus, and 
within which they emit tubes. 
Too nih stress has been, I think, laid upon the 
resemblance in the vessels so much insisted on by 
Desine Mr. brown has remarked, that the natural 
state of Cycadez is to have many embryos. Judging, 
l suppose from the presence of the sacs existing in 
apex of the albumen, in this view he is as usual 
correct, it is a curious, fact that in Cycas circinalis and 
in the Assam species the alteraate tessellations caused 
s by the foliation and floration of distinct years is lost 
Meh of in the undivided base of the trunk. - 
Within the albuminary membrane, and in the | 
debis fluid that it sutipins, the origin: of cellular 
