238 NOTES AND COMMENTS [ocroBER 
of Physiology ” from that expressed in Green’s “ Prolegomena,” or in 
Newman’s “Sermons,” or in Whistler's “Gentle Art,’ or in Meredith’s 
“Ballads of the Earth.” Altogether apart from subject-matter, the 
intellectual note of these is quite different from that which characterises 
the immortal text-book referred to, and what we wished was that the 
Professor had told us what his particularly well-marked differentiating 
feature—obscured by the word “scientific ”—really meant. 
Much more satisfactory was the concluding part of the address, in 
which the President discussed the solidarity and internationalism of 
science. “The man of science,’ he said, “cannot sit by himself in his 
own cave, weaving out results by his own efforts, unaided by others, 
heedless of what others have done or are doing. He is but a bit of a 
great system, a joint in a great machine, and he can only work aright 
when he is in due touch with his fellow-workers. If his labour is to 
be what it ought to be, and is to have the weight which it ought to 
have, he must know what is being done, not by himself, but by others, 
and by others not of his own land and speaking his tongue only, but 
also of other lands and other tongues.” That this is being increasingly 
recognised is made evident in many ways—by international congresses 
and bibliographies, by international co-operation in great enterprises 
like the Antarctic Expedition, and in smaller endeavours like the pro- 
duction of Natural Science. 
More Pleurococcus. 
ANOTHER filament-forming Alga, to which its discoverer, Miss Snow 
(Annals of Botany, vol. xiii. No. 4, p. 189), has provisionally given the 
name Pseudo-Pleurococcus, has been separated from the aggregate of 
small unicellular green forms, so long known under the collective name 
of Pleurococcus vulgaris. The new form differs in the unicellular state 
from the true Plewrococcus vulgaris, which we are glad to see Miss 
Snow still recognises as a constant non-filament-forming species, by 
the possession of a pyrenoid and of a lateral aperture in the chloro- 
plast, while it has the power of forming filaments when grown in 
certain nutritive solutions. 
It appears also to be distinct from the filamentous form of Plewro- 
coccus described by Chodat, in which the pyrenoid was absent, and 
which could not be distinguished in the unicellular state from the true 
Pleurococcus. In truth, the layer of green unicellular organisms so 
frequently met with on the bark of trees, etc., seems to consist, not of 
a single polymorphic species, but rather of a considerable number of 
real species, which may be isolated from one another only by the 
employment of certain modifications of the well-known methods of 
bacteriology, especially by rigid attention to the sterility of cultures. 
