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PROGRESS OF MICROSCOPICAL SCIENCE. 
of Dublin, has now discovered what he supposes to be another species 
of this genus as yet undescribcd living in the substance of Schizonema 
fronds, and in the paper above quoted details the results of his 
investigations into its life-history. It may first be observed that the 
patience and labour bestowed on this investigation are to be valued 
apart from the result. Nothing however can be clearer, on Professor 
"Wright’s own showing, than that the plant he describes is no chloro- 
chytrium according to Cohn’s diagnosis. We do not for one moment 
doubt the accuracy of Professor Wright’s observations so far as they 
go: but when his plant, as he himself plaiuly states, is distinguished 
from Cohn’s by a “ totally different process of the formation of the 
zoospores, and the occurrence of large and small zoospores ” (the italics 
are ours), surely something more than a specific difference is present. 
As to this matter of large and small zoospores, “ the true significance 
of this fact” Professor Wright is “at present unable to determine.” 
Many things are, of course, possible, and we have neither desire nor 
space to speculate on the probability of their conjugating besides 
fulfilling the function of vegetative reproduction. We will mention 
only one suggestive instance, that of Ulothrix zonata, which produces 
macrozoospores and microzoospores, the latter of which conjugate 
among themselves, but the former never, nor the one laud with the 
other, while both under favourable circumstances are capable of the 
asexual reproduction of the mother plant. Now, in this case of Chlo- 
rochytrium may not some of these forms of conjugation take place? 
This important point was not cleared up. It would be fortunate if 
Professor Wright himself discovered the true solution of this ques- 
tion. At present the value which the paper appears to have is as a 
partial description of the life-history of what seems to be a yet unde- 
scribed plant. 
The Influence of Light upon the Development of Bacteria. — Mr. A. 
Downes and Mr. T. P. Blunt sent the following note to ‘ Nature ’ 
(July 12), on this subject: 
We have been engaged during the last few months on an investi- 
gation into the effect of light upon the development of Bacteria in 
certain of those solutions in which they are usually produced. 
We reserve the details for a paper which we hope to submit to the 
Royal Society in the course of their next session, but wish to state, 
in the meanwhile, that the first portion of our inquiry has led us to the 
following conclusions : 
1. That light is inimical to the development of Bacteria. 
2. That under favourable conditions it may prevent their de- 
velopment. 
3. That under less favourable it may not prevent but only retard. 
4. That for the full effect of light to be produced direct insolation 
is necessary. 
5. That those conditions which tend to neutralize the action of 
light are the same which are known to favour processes of fermenta- 
tion and putrefaction. 
6. That the fitness of the solution to serve as a nidus is not 
destroyed by insolation. 
