SCIENTIFIC SUMMARY. 
205 
gressive change in both nebulae, most remarkably in that of 77 Argus ; the 
smaller class of nebulae are also constantly changing from year to year, 
giving new life to such observations. The bright yellow line and occasional 
red line seen in the spectrum of 77 Argus for five or six weeks, four or five 
years ago, have never been since seen. — The definition of the Melbourne 
reflector has been wonderfully improved by better adjustment, and it now 
seems likely to answer every expectation. — The great Paris reflector is of 
the Newtonian, not, as was stated in our last number, of the Lemairean or 
u front view ” construction. 
BOTANY AND VEGETABLE PHYSIOLOGY. 
The Formation of Starch in Chlorophyll-grains (in the green parts of 
plants), under the action of light, was made out by Sachs ten or twelve years 
ago, and has been confirmed, and the conditions recently studied in various 
ways by Famintzin, Kraus, and Godlewski. It is maintained, says “Silliman’s 
American Journal,” if we rightly understand, that this starch is directly 
formed from carbonic acid under the action of light, i.e. is a primary pro- 
duct of assimilation. Bohm, of Vienna, who contested this, but whose view 
according to Sachs “ has already been sufficiently refuted,” has returned to 
the subject, with new observations and experiments, and now asserts, upon 
reasons stated, that “The starch appearing in the seed-leaves of plantlets of 
cress radish and flax, is not a direct assimilation-product, formed by the 
immediate decomposition of carbonic acid, but a transformation-product 
from a reserve of nutriment already present.” One would surely expect that 
the primary product of assimilation of carbonic acid and water would be an 
organisable plasma from which the starch-grains in question are constituted, 
not an organic structure such as a starch-grain is. It is not clear that there is 
much real difference between the two views, at least between those of Sachs 
and Bohm. For since starch, as the former explains, is formed and reformed in 
various parts of the plant and away from light and from chlorophyll, and in 
the leaf is allowed to be only one of the products of assimilation, Sachs’ 
assertion that starch in chlorophyll-grains is “a product of assimilation,” and 
Bohm’s that it is not “a direct assimilation-product,” are by no means in 
necessary contradiction. Nor is there apparent reason for supposing that a 
starch-grain in a potato-leaf is differently originated from one in a potato, 
except that the former is constructed of new-formed material. 
The Plants of Guailaloupe Island. — At a recent meeting of the American 
Academy of Arts and Sciences, Mr. S. Watson presented a paper on a col- 
lection of plants recently made by Dr. E. Palmer, in Guadaloupe Island, off 
Lower California. It was found to contain 119 species, including twenty- 
one belonging to the higher cryptogamic orders, besides a dozen of probably 
recent introduction. The number of new species is twenty-two, with two 
new genera, almost all nearly allied to Californian species and genera. Of 
those before known, all are Californian, and most have a wide range through 
that State. The flora of Mexico is scarcely represented, but on the other 
hand some fresh indications are found of a connection between our western 
flora and that of South America. 
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