114 Chronicles of Science. (Jan. 
it applies should be designated raphis bearing or raphidiferous. 
Besides Onagraces, Dioscoracee, Aracer, and Asparagacese are 
spoken of as truly raphidiferous orders. 
M. B. Corenwinder has been making a series of observations upon 
the expiration of leaves by day and night. He finds that the ‘amount 
of carbonic acid exhaled at night varies with the temperature and 
ceases at zero; nor is the property of absorbing carbonic acid and 
again decomposing it found in very young leaves and buds. Adult 
leaves, however, never exhale carbonic acid in the open air, and when 
they receive a full supply of light from all parts. The question 
whether leaves coloured red, brown, or purple, possess the same pro- 
perties as green leaves, has also occupied his attention, and he asserts 
that they differ in nothing from green plants in regard to the pro- 
perty of absorbing carbonic acid under the influence of light, and ex- 
haling it in darkness. It is therefore inexact to say, in an absolute 
manner, that it is by their green parts that leaves decompose carbonic 
acid under the influence of sunlight. 
The abundance of minute organisms found at deep-sea bottoms in 
the Atlantic and elsewhere, and the remarkable facts disclosed by Dr. 
Wallich’s deep-sea soundings in the expedition of Capt. M‘Clintock, 
gave some colour to the idea that the vegetable Diatomacez exist in a 
living state at great depths, and Dr. Stimpson, an energetic young 
naturalist connected with the Smithsonian Institution at Washington, 
who examined the specimens taken at the depth of 2,700 fathoms, in 
latitude 46 N. and longitude 168 E., by Lieutenant Brooke, found 
some startling appearances. The armature consisted of three quills, 
each about three inches in length, fastened together, and placed in such 
a position that, when the lead struck the bottom, the quills would be 
forced perpendicularly into it, and thus become filled with mud from 
a stratum a few inches below the general surface of the sea-bottom. 
One of these quills, cut in two in the middle, contained Diatoms, appa- 
rently Coscinodisci, which appeared to Dr. Stimpson to be undoubt- 
edly living, judging from their fresh appearance and the colours of 
their internal cell-contents. Dr. Wallich, however, argues that 
although the soft parts are retained in specimens obtained from ex- 
treme depths, they differ materially both in aspect and quality from 
those of Diatoms known to be living. Such Diatoms never present 
a trace of locomotion, which is so tenaciously retained by Diatoms 
under all other circumstances. Moreover, the Coscinodisci, which 
constitute the largest proportion of Diatoms found in deep-sea depo- 
sits, are essentially inhabitants of shoal water. They do not live im- 
bedded in mud, but the upper waters,teem with their frustules. Dr. 
Wallich therefore inclines to answer the question decidedly in the 
negative. 
