9 8 
Notes. 
THORNS WITH CORKY BASES— A CORRECTION.— I am 
desirous to publish the following correction to my list of plants having 
thorns with corky bases, contained in a note by Dr. Trimen of Ceylon, 
which, although dated January 16, 1893, has only just reached me : — 
‘At p. 165 of the sixth volume of the Annals of Botany, among the 
plants recorded by Mr. Barber as having corky thorns, is Ailanthus 
malabarica, which is entered on the authority of a photograph taken 
at Peradenyia by Mr. Potter. The name is erroneous, the tree being 
Zanthoxylum Rhelsa. But I believe that at the time the photograph 
was taken, the plant had by some accident a wrong label attached to it.’ 
Zanthoxylum Rhetsa is already in my list; and, as Ailanthus mala- 
barica is the only example quoted of Simarubeae, that order will have 
to be ruled out. Many additions might doubtless be made by 
travellers in the tropics with the means of identifying forest-trees. 
The only case I could be certain about in the Leeward Islands is the 
common sand-box tree, Hura crepitans, which has thorns with stony 
bases exactly like those on the specimen of Erythrina lithosperma in 
the Botanical Museum at Cambridge. 
C. A. BARBER. 
Royal Indian Engineering College, 
Cooper’s Hill. 
THE CYTOLOGY OF SAPROLEGNIA. — The almost simul- 
taneous appearance of Mr. Trow’s interesting and elaborate paper on 
the ‘ Karyology of Saprolegnia ’ in the Annals of Botany for Decem- 
ber, 1895, and of mine ‘On the Cytology of the Vegetative and 
Reproductive Organs of the Saprolegnieae ’ in the Transactions of the 
Royal Irish Academy (read February 19, 1893, revised for press 
June, 1895), renders it desirable that I should make some remarks on 
the points at issue between us. 
My first and gravest criticism on matters of fact is that Mr. Trow 
has overlooked the existence of four chromosomes in the vegetative 
nuclei, to which he ascribes only a single chromosome ; he admits 
that his ‘ observations on this point might well have been more 
extensive’ (p. 624) \ Considering the importance he attaches to the 
1 The context in my first publication on this subject (Comptes Rendus, CVIII, 
1889) would seem to render it plain that my observations on nuclear division 
referred to the vegetative hyphae. But Mr. Trow writes ‘ as he expressly states 
that divisions do not occur in the oogonia, I conclude that he observed these 
phenomena in the antheridia’ (p. 629) — a curious non-sequitur. 
