Notes on Recent Literature . 339 
between 35° and 44 n . One would then expect that temperatures 
which failed to produce a permanent rise in the respiration would 
also not bring about a rise in the equilibrium concentration of sugar. 
The authors have not been able to find any significant differences 
in the amount of diastase before and after heating, and conclude 
that the accumulation of sugar after heating does not depend on an 
increased formation of diastase, but is brought about in the way 
already indicated. 
They also record experiments on the effect of etherisation on 
halved potato tubers. They found that the maximum in the curve 
of respiration following the injury by halving was not affected, but 
was reached rather later (owing to “ narcosis ” of the protoplasm); 
the subsequent fall was slower in the etherised potatoes. No 
alteration of the immediate or subsequent changes of sugar concen¬ 
tration was observed. Etherisation thus differs from heating ; it is 
apparently less drastic. The difficulty of ether penetrating into the 
interior of the tuber may perhaps account for this; at any rate the 
“ narcosis ” suggests comparison with the inhibition produced by 
heating. Further comparison is not possible as the experiments 
are very few, and whole potatoes were not used in any of the 
etherisation experiments. 
Further contributions on the same lines will he awaited with 
interest, and more experiments with the same material would be of 
value in elucidating the respiratory problems which are involved. 
D.T. 
Plant-Animals. 
Under this title Professor Keeble publishes in the new series 
of “ Cambridge Manuals of Science and Literature ” an account 1 of 
the natural history of those fascinating marine worms Convoluta 
roscojfensis and C. paradoxa. Those botanists who are not familiar 
with Professor Keeble’s papers (partly in conjunction with Professor 
Gamble) on this subject should certainly get and read this little 
book. And not only for the extraordinary attractiveness of the 
facts described and the problems involved, which Professor Keeble 
has largely elucidated in a singularly able and acute manner, but 
also because the questions raised by these worms are of as much 
interest to the botanist as to the zoologist, if indeed they are not of 
even greater importance to the student of plant-life. This study is 
indeed a real study in biology, the science of life. It has for its 
object the whole complex of interrelations between a given animal 
and a given plant, and its problems are some of the fundamental 
problems of living protoplasm. 
The story of how the two species of Convoluta, each sharply 
restricted to a different and perfectly definite zone on the sea-shore, 
are inhabited, the one by a green and the other by a brown uni¬ 
cellular alga, and of how they have given up eating solid food after 
the manner of animals, because they are entirely dependent on their 
lodgers is interesting enough and partly familiar already. But the 
further story of how each species of worm exhibits a series of ex¬ 
tremely regular and astonishing movements, in relation to the tides, 
which result in constantly keeping it in the ideally best position in 
1 “Plant-Animals: a study in symbiosis,” by Frederick Keeble. 
Pp. viii and 163. Cambridge, at the University Press, 1910. 
Price One Shilling. 
