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POPULAR SCIENCE REVIEW. 
tively brief space of time. His diagrammatic sketches of a cell, which 
show the several changes it has undergone in the course of about sixteen 
minutes, are full of interest, and they will at once recall to the mind of the 
student of human microscopic anatomy the sort of thing seen when a fresh 
piece of certain mucous membranes is submitted to examination. We think, 
in regard to those observations, that what the writer remarks is extremely 
probable— for, indeed, we have ourselves witnessed it when employing im- 
proved illuminators — viz. that in some of the specimens, in which appa- 
rently two distinct cells existed, there really was a connecting cord, which 
was “ drowned” by the method of throwing the light on the object. He 
says, p. 41 : “ At first there was at the base of the cell a little mass on a 
short footstalk, and a larger mass near the upper end, and these seemed 
quite separate. Nevertheless, they may have been connected by a fine and 
invisible thread of protoplasm, for on two other occasions, whilst one mass 
was rapidly increasing and another in the same cell rapidly decreasing, I was 
able, by varying the light and using a high power, to detect a connecting 
thread of extreme tenuity, which evidently served as the channel of commu- 
nication between the two.” 
Of the many experiments the author has made with reference to the 
digestible power of certain plants, some of the most interesting are those he 
conducted on the Drosera rotundifolia. These showed that raw flesh, when 
placed upon the leaf, was completely digested in a comparatively short space 
of time. But one would have thought that bone was entirely beyond 
the power of the plant. It does not appear so from the following account 
which Mr. Darwin has given: — “Dr. Burdon Sanderson suggested tome 
that the failure of Drosera to digest the fibrous basis of bone might be due 
to the acid being consumed in the decomposition of the earthy salts, so that 
there was none left for the work of digestion. Accordingly, my son 
thoroughly decalcified the bone of a sheep with weak hydrochloric acid, and 
seven minute fragments of the fibrous bases were placed on so many leaves, 
four of the fragments being first damped with saliva to aid prompt inflection. 
All seven leaves became inflected, but only very moderately, in the course 
of a day. They quickly began to re-expand, five of them on the second 
day, and the other two on the third day. On all seven leaves the fibrous 
tissue was converted into perfectly transparent, viscid, more or less lignified 
little masses.” Thus we see that even decalcified bone was nearly com- 
pletely dissolved by the plant, although evidence of absorption was not as 
clearly shown. Among other curious experiments conducted on the Drosera 
was one of some importance, as it shows what a difference may exist be- 
tween the action of a poison on animals and plants. It was the trial of 
cobra poison, which, while it is most deadly in its action on animal life, does 
not appear to have any influence on the vitality of the plant. The author 
says that “from these facts it is manifest that poison of the cobra, though 
so deadly to animals, is not at all poisonous to Drosera, yet it causes strong 
and rapid inflection of the tentacles, and soon discharges all colour from the 
glands.” Indeed, he seems to think that in some way or other it acts as a 
stimulant to the protoplasm of the plant. 
Another point which Mr. Darwin has investigated, and with strange 
results, is that of the direction of the inflected tentacles. And though he 
