798 Recent Literature. [ October, 
cited.” Now, inquires Marey, is this harmony preéstablished, or 
rather is it formed under the influence of function in different 
creatures? Just as we see muscles increase in volume by use, so 
we may observe them, under the influence of more extended 
movements, acquire a greater length. “Can we see a displace- 
ment of the tendinous attachments of the muscles to the skele- 
ton, under the influence of changes in the force of muscular trac- 
tion? This problem he proposes to settle by experiment, but 
before doing so he feels obliged to invoke the pagiirnn e 
theory, and to show that all through nature, and even in medica 
science, when an organism, as also an organ, is placed under new 
circumstances it must change in form, and that “ function makes 
the organ.” His philosophy is a substratum of Lante 
2. é., change in the environment ensuring change in the organ ~ 
in the organism; with a superstructure of Darwinism, or — 
selection, acting after a change or variation has bead a 
The application of these views is seen in chapter 1x, Variability = ¢ 
the Skeletgn, an essay of great interest from the point of view ‘ 
the laws underlying the sciences of comparative anatomy an 
palzontology. te ae 
Professor Marey shows in this chapter how yielding 1n ‘ : 
nature is the bony system of the vertebrates during life; t a 
pressure or tension, however slight, will produce the stranges 
changes of form; the bone, he goes so far to say, is “like soft Kee 
which yields to all external forces,” and we may say of the skele 
ton, that “its form is that which the soft parts with which . 1s 
surrounded permit it to assume.” He cites cases in surgery 4" 
medicine, as well as comparative anatomy, in proof of the shee 
sition “that in the form of the bony structure, everything bea 
the trace of some external influence, and particularly of the fans: 
tion of the muscles. There is not a single depression oF projec 
tion in the skeleton, the cause of which cannot be found 1 re 
external force, which has acted on the bony matter, either to 
indent it, or draw it forward.” : ‘mals 
The great variety of forms in the skeletons of different age" 
corresponds with the diversity of their muscular systems. ~* . 
if the muscles modify the bones, what brings about the betes 
changes in form of the muscles? Marey attempts to demonstra . 
that the power to which the muscular system is subjected ene 
to the nervous system. “The nature of the acts which peretiev 
commands the muscles to perform, modifies the muscles then 
selves, in their volume and their form, so as to render them se 
ble of performing these acts in the best possible manner. ve 
author, from facts in medicine and surgery, shows that it 1S peor 
ment or use which maintains the existence of the muscle; 4 
paralysis or dislocation of bones rendering muscles pouemtst 
muscle may wholly disappear, undergoing either fatty degen 
tion or fibrous transformation. ne 
