330 
Notes . 
Whether anything corresponding to ‘ double fertilization ’ (a term here obviously 
inappropriate) occurs is not certain, though the evidence points to it. The definitive 
nucleus begins to divide before the fertilized egg. Its divisions are rapid and 
simultaneous, and, as might be expected from its multinuclear origin, the endosperm 
nuclei are large, with a great number of chromosomes and several nucleoli. They 
are distributed in the parietal layer of protoplasm, and walls appear only at a very 
late stage, forming a loose tissue in the lower part of the embryo-sac, which is entirely 
used up by the growing embryo. 
These investigations were carried out in the Botanical Laboratory of the South 
African College, Cape Town, at the suggestion and under the supervision of Professor 
Pearson ; they are being continued at the Botany School, Cambridge. 
E. L. STEPHENS. 
Newnham College, Cambridge. 
THE EMBRYO-SAC OF PANDANUS. PRELIMINARY NOTE.— A 
preliminary study of the embryo-sac of Pandanus which I have recently made shows 
that it differs decidedly from the usual Angiospermous type, and to some extent 
resembles more nearly that of Pepero?nia. Two species of Pandanus have been 
examined — P. odoratissimus and P. Ariocarpus — which agree very closely in the 
structure of the embryo-sac. Up to the second nuclear division in the young sac, 
Pandanus agrees with most of the Angiosperms, and at this stage the embryo-sac 
shows the usual two nuclei at the micropylar and chalazal ends. The two micro- 
pylar nuclei undergo no further division, but the chalazal nuclei divide until there 
may be twelve of these, and this seems to be the normal number, to judge from 
an examination of a number of the largest sacs that were studied. These always 
showed two nuclei at the micropylar end, surrounded by a relatively small amount 
of granular cytoplasm, while the large chalazal nuclei were scattered, apparently 
without any definite order, in a large mass of granular, more or less vacuolated, cyto- 
plasm, which filled nearly one-third of the sac. The differentiation of antipodal 
cells was visible, and there was no certain evidence of nuclear fusions. 
Whether any further differentiation of the embryo-sac structures occurs before 
fertilization remains to be seen. 
DOUGLAS H. CAMPBELL. 
Stanford University, 
Feb., 1908. 
SUPPLEMENTARY NOTE TO ‘ STUDIES ON SOME JAVANESE 
ANTHOCEROTACEAE '. 1 — Since this paper was written, Dr. Lang 2 has published 
an account of the sporogonium of Notothylas Breutelii , which closely agrees with 
that given in my paper for N. javanicus . The most marked difference is the greater 
development of sporogenous tissue from the endothecium in JSJ. Breutelii. 
DOUGLAS H. CAMPBELL. 
Stanford University. 
