1875.) Notices of Books. 261 
claim to no originality, and the subject-matter is expanded from 
a lecture delivered before the Microscopical Society of Liver- 
pool during the present year. The Author is evidently well 
acquainted with his subject; he is well acquainted with the 
literature of it, and quotes a multitude of men, from Schleiden, 
Schwann, and Leydig, to Beale, Herbert Spencer, and Huxley. 
He sums up the whole variety of opinion on the subject in the 
following opening sentences, which divide them into—‘ 1. Those 
which require the addition to ordinary matter of an immaterial 
or spiritual essence, substance, or power, general or local, whose 
presence is the efficient cause of life; and 2. Those which attri- 
bute the phenomena of life solely to the mode of combination of 
the ordinary material elements of which the organism is com- 
posed, without the addition of any such immaterial essence, 
power, or force).” Up to the year 1835 the old idea of a vital 
fluid was in some form or other dominant; in that year the 
coup de grace was given to the theory by Dr. Fletcher, of Edin- 
burgh, who, in his ‘‘ Rudiments of Physiology,” discussed the 
merits of the theory in a perfectly calm and judicial manner, and 
decided against it. The protoplasmic theory was proposed so 
recently as 1860, by Dr. Lionel Beale, who describes fundamental 
germinal matter, or bioplasm, as ‘‘ always transparent and co- 
lourless, and, as far as can be ascertained by examination with 
the highest powers, perfectly structureless, and it exhibits these 
characteristics at every period of its existence. . .. Norcan 
any difference be discerned between the germinal matter of the 
lowest, simplest, epithelial scale of man’s organism, and that 
from which the nerve-cells of his brain are to be evolved.” 
Then follow commentaries on Beale’s nerve theory and muscle 
theory; then various definitions of life, among which we may 
notice De Blainville’s ‘‘ Life is the two-fold internal movements of 
composition and re-composition ,at once general and continuous.” 
The concluding chapter treats of Materialism. The Author 
shows how frequently the term is misunderstood or wrongly 
defined, and shows, further, that religion and science need not 
be at war. The facts of the theory of protoplasm are clearly set 
forth in this very readable work, and the non-scientific man may 
by its help make himself well acquainted with one of the most 
prominent physiological theories now before the world. 
The Elements of Embryology. By Micuaret Foster, M.A., 
M.D., F.R.S., Fellow of and Prelector in Physiology in 
Trinity College, Cambridge, and Francis M. Barour, B.A., 
Fellow of Trinity College, Cambridge. London: Mac- 
millan and Co. 1874. 
Tue Cambridge Physiological Laboratory is already beginning 
to bring forth good work, and it is satisfactory to see the name 
