SEPTEMBER 8, 1899. ] 
lies hid. The attacks upon it from the 
direction of physical chemistry and phys- 
iological morphology, of irritability, of 
ecology, and of cytology, are the concen- 
trating attacks of various divisions of an 
army upon a citadel, some of whose outer 
defences have already been captured. The 
innumerable observations are devised along 
parallel lines of approach, and each division 
of the army is creeping closer and closer to 
the inner defences, which yet resist all 
attacks and hide the long-sought truth. 
We see yet no breach in the citadel. Here 
and there we seem to approach more closely 
and at certain points are getting glimpses, 
through this loophole or that, of inner 
truths, hidden before. 
One outer circle of defences yet remains 
untaken, and until that falls it would seem 
that there is little hope of capturing the 
inner citadel. We must know more of the 
constitution of dead substances chemically 
related to the living ones. When the stu- 
dents of chemistry can put the physiologists 
into possession of the facts regarding dead 
proteids we shall renew the attacks more 
directly, with greater vigor and greater 
hope of success. 
That ultimate success is to crown our 
efforts there is little reason to doubt. Ten 
years ago we little dreamed of the tre- 
mendous strides as since made toward the 
interpreting of life’s central truth. The 
success of the past is the best augury for 
the future. The brilliant researches upon 
the chemistry of carbon compounds inspire 
us with renewed hope and put into our 
hands almost daily new weapons. 
It is not possible to prove to-day that 
life and death are only a difference in the 
chemical and physical behavior of certain 
compounds. It is safe to say that the future 
is likely to justify such an assertion. In 
the meanwhile we press forward along the 
whole line. Botany is more than ever full 
of meaning, because with its sister sciences 
| SCIENCE. 
_Macfarlane entitled 
ool 
it is no longer seeking things, but the rea- 
sons for things. Caries R. Barnes. 
UNIVERSITY OF CHICAGO. 
SECTION A—ASTRONOMY AND MATHE- 
MATICS. 
Tur address of Vice-President Alexander 
‘The Fundamental 
Principles of Algebra,’ and the ‘ Report on 
Progress in Non-Euclidean Geometry,’ by 
Professor George Bruce Halsted, of the 
University of Texas, are both to be pub- 
lished in full in Scrence and will not be 
treated further here. 
A Report on the Recent Progress in the 
Theory of Linear Groups, presented by Pro- 
fessor L. E. Dickson, of the University of 
California, was of the nature of a supple- 
ment to the report on finite groups, read at 
the last annual meeting of the Association, 
by Dr. G. A. Miller, of Cornell. It is in- 
tended for publication in the Bulletin of the 
American Mathematical Society, in which the 
report of Dr. Miller appeared last year. 
Part I. of the present report gives the 
general theorems relating to the canonical 
form of finite groups of linear substitution 
and to the generators of such groups. After 
a complete enumeration of the binary and 
ternary collineations in their historical set- 
ting, a number of special quaternary linear 
groups, particularly the famous one of order 
51,840, are considered. 
Part II. treats of linear groups in a Galois 
field, their order, generators, factors of 
composition and the isomorphisms existing 
between them. The Galois field is defined 
and a full bibliography added. The gen- 
eral linear homogeneous group, the linear 
fractional group, the Abelian linear group 
and its generalized form, the first and second 
hypoabelian groups, the orthogonal group, 
other linear groups with a quadratic invari- 
ant or a special invariant of degree q, the hy- 
perorthogonal group and the hyperabelian 
group areall treated in turn. A number of 
