Miscellaneous. 154 
has attained its greatest exuberance, namely, when the summer 
months are past and the light is beginning to decrease in its in- 
tensity and the days to shorten. So exactly, indeed, are the ener- 
gies of the plants regulated by the amount of light to which they 
are exposed, that a constant arrangement, such as that here des- 
cribed, affords an excellent indication of the variation of the seasons 
in different years, or might even be made a rough measure of the 
total amount of light from month to month. 
But while the demand for carbonic acid on the part of the plant 
varies in this manner with the seasons, the amount of that gas pro- 
duced by the respiration of the fish is very nearly the same all 
through the year. Whence, then, does the plant obtain that addi- 
tional quantity of food which its stimulated energies require during 
the spring and early summer months, and which its rapid and 
luxurious growth show to be readily supplied? After what has 
been stated, I think the source must be apparent to every one: it 
is the carbonic acid which has been gradually accumulated, and 
rendered innocuous to animal life from its being held in combination 
with carbonate of lime, in so marvellous a manner during the 
winter months. Stored up, yet held in feeble combination, a com- 
bination so weak that the vital forces of the fresh-growing vegetation 
can easily overcome it, and resolve once more into carbonate of lime, 
carbon, and oxygen the bicarbonate of lime contained in the water *. 
Thus beautifully are the necessary irregularities in the purifying 
action of the plant compensated and provided for, that the balance 
of existence between the animal and vegetable organisms be not 
disturbed or overthrown, and thus additional proof is furnished, if 
such were needed, of the wisdom of that creative power that has 
ordered all things to work together for good, and by endowing certain 
bodies with such seemingly minute and insignificant affinities, main- 
tains the glorious harmony of the whole. 
MISCELLANEOUS. 
Errata in Localities of Indian and Burmese Squirrels. Necessity of 
defining more exactly what is understood by India. 
To the Editors of the Annals and Magazine of Natural History. 
_ Genttemen,—In Dr. Gray’s very useful Synopsis of the Asiatic 
Squirrels in the Collection of the British Museum, published in the 
October number of the ‘ Annals,’ some of the localities are incorrect. 
i venture to point out two or three such cases. I do not suppose 
that Dr. Gray is responsible for their accuracy, as he has doubtless 
taken them from the specimens in the British Museum; but, in any 
* The rapid growth of submerged vegetation in rivers and waters containing 
a considerable amount of carbonate of lime must have been observed by all 
interested in the subject, in some cases obliging the cleansing of such streams 
three or four times during the year. 
