74 Scientific a 
a related to those of the West Indies, but situated upon the 
cific si 
fossiliferous beds containing other fossils, thus situated. The well 
known existence of elevated coral reefs in the East Indies and 
Polynesia, and in the West Indies, proves nothing of the sort, for 
what little relationship exists between the corals of those regions 
ean be explained in other ways. We think it — that while 
certain geologists find it necessary to force the Gulf Stream across 
the Isthmus during the warm ara period, others find it quite 
as important to have it turned out of the Atlantic across the 
Isthmus during the Glacial paid: Both — seem equally 
_ nating be VERRILL. 
rinciples of Animal Mechanics ; by th tev. SAMUEL 
1873. (Longmans, Green & wt oo volume is the result of 
scles an 
action; theory of the sane ana iboadiber joints: principle of least 
action ’ applied to the arrangement of the muscular fibers of the 
eart, etc. 
The author has throughout reduced his elaborate observations 
made in the dissecting room to numbers, and then has availed 
himself of the eee of geometry and mechanics in their far- 
ther discussion. Especially in his treatment of muscular curved 
surfaces, both ellipsoidal and skew surfaces, has the author made 
fall 1 use of the mathem 
As a result of cre ~eadinies for the hip, shoulder, and other 
joints of many animals, Dr. Haughton states that he has “ never 
met with any exception to the followi wing took epg which may 
be Hd sete as summing up my results :’ 
Each muscle is constructed in relation to its joint in such 
a manner as to perform one kind of work only: and it performs 
ge. 
2. The number of muscles s employed * ——_ by the 
number of distinct actions required from th 
3. The shape and form of the bones employe are the necessary 
consequence of the shape and power of the muscles in action. 
4. The smallest muscle in the seatbicathonis is as carefully adapted 
to its conditions of maximum work as the largest muscle. 
rom these propositions, supposed to be extended to the action 
of every muscle and joint, it appears to me to follow as necessary 
consequences: 
1. That a forcsceiiig Mind planned the type of the limb, and 
of its actions. 
The sed of the limb and of its necessary actions being given; 
the number, shape, and arrangement of the necessary muscles 
