SCIENTIFIC SUMMAEY. 
417 
only. It •will be observed that, speaking generally, the stars which the 
spectroscope shows to be moving from the earth, as Sirius, Betelgeux, Bigel, 
Procyon, are situated in a part of the heavens opposite to Hercules, towards 
which the sun is advancing ; while the stars in the neighbourhood of this 
region, as Arcturus, Vega, and a Cygni, show a motion of approach. There 
are, however, in the stars already observed, exceptions to this general state- 
ment; and there are some other considerations, as the relative velocities of 
the stars, which appear to show that the sun’s motion in space is not the 
only or even in all cases the chief cause of the observed proper motions of the 
stars. In the observed stellar motions we have to do probably with two 
other independent motions — namely, a movement common to certain groups 
of stars and also a motion peculiar to each star. Thus the stars (3, y, d, f, £ 
of the Great Bear, which have similar proper motions, have a common 
motion of recession ; while the star a of the same constellation, which has 
a proper motion in the opposite direction, is shown by the spectroscope to be 
approaching the earth. Prom further researches in this direction, and from 
an investigation of the motions of stars in the line of sight in conjunction 
with their proper motions at right angles to the visual direction obtained by 
the ordinary methods, we may hope to gain some definite knowledge of the 
constitution of the heavens. This discovery supports, in a somewhat strik- 
ing manner, ’’proceeds Dr. DelaRue, “the views which Mr. Proctor has been 
urging respecting the distribution of the stars in space.” 
BOTANY. 
The Geographical Distribution of Composites. — Mr. G. Bentham read a 
paper on this subject at two meetings of the Linnaaan Society, in con- 
tinuation of his paper on the structure of the same order of plants. The 
genera and species of this largest order of flowering plants are about 
equally distributed between the Old and New World; of the genera, 
about 410 are found in the former and 430 in the latter ; of species, about 
4,400 in the Old World and a rather larger number in the New. Not 
quite 70 species are common to the two hemispheres, and these mostly 
belong to the extreme northern regions ; a few are common to New 
Zealand and Antarctic America; not more than a dozen tropical species are 
found in both the Old and New World, and some of these are coast 
plants. The form which Mr. Bentham looks on as prototypic, and 
possibly ancestral to the whole order, includes a few closely allied 
genera, distinguished by their regular corolla, belonging rather more to 
the American than the Old World distribution, being found in Chili, with 
an outlying genus in St. Helena. Other types, apparently of great 
antiquity, are found in Africa, Australia, and Western America. Since the 
separation of the Indo-Malayan and Australian regions from one another, 
there appears to have been a continuity of races of Compositse across the tropics 
from south to north. The paper, which enters exhaustively into the dis- 
tribution of the various tribes and more important genera, is published in 
the “Journal of the Linnsean Society.” T 
VOL. XI. — NO. XLY. 
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