158 THE AMERICAN MONTHLY. [August. 



environments which harm it, a medical work to be of scientific value should, so far 

 as the present state of knowledge permits, keep it constantly in view. Our author, real - 

 izing this fact, emphasizes it in these words : — ' The full comprehension of the function 

 of this substance (protoplasm) lies at the root of the greater part of physiology.' To 

 make medicine a science this motto must be at its foundation, otherwise it remains, as 

 it has necessarily been in years gone by before protoplasm had been guessed at and 

 studied, the mere mastering of numerous empirical cures, whose operation was only 

 known by their results. It is, of course, well understood that the science is in its infancy 

 as yet, and it will be long before the healing science can become one of precision. 

 Only second in importance to the continual reference of physiological action to its real 

 seat, the protoplasm of gland muscle and nerve, is the history of these active tissues 

 and their embryology ; it is very probable that the future of medicine will find a vast 

 new territory as this subject becomes more clearly understood. Meanwhile the stu- 

 dent of physiology should be trained in this as a part of his course. Dr. Yeo has 

 given this subject a fuller study than usual. 



It is not only the student of medicine who will use this work, but the general prac- 

 titioner or general reader in any sphere will find it a most excellent treatise on the 

 subject. While written particularly for the medical student, it fairly comes within the 

 range of any reader who wants to know how his body is constructed, and we gladly 

 recommend it to all our readers. The illustrations are very commendable, as to 

 execution, but more particularly as to design, and with' their help we do not see how 

 any one who gives the highly complex subject honest study can fail of comprehending 

 the author's meaning. 



Exchanges. 



[ Exchanges are inserted in this column without charge. They will be strictly limited to mounted objects, and 

 material for mounting.] 



OFFERED, — Diatomaceous earth from Thibet, various localities (12,000 feet); also, material and slides of 

 diatoms from Scottish Highlands, and continental foraminiferae. WANTED. — Slides of American diatoms, 

 insects, or botany. W. D. STEWART, 2 Gilmore Terrace, Edinburgh, Scotland. 



OFFERED. — Sections of vegetable ivory and slides of crystalized maple sugar. Good mounts taken in 

 exchange. WM. LIGHTON, 106 Filth Avenue, Leavenworth, Kansas. 



WANTED. — Parasites and books on Parasites and other micro, subjects. Will give Anatomical, Pathologi- 

 cal, Botanical, Micro-fungi, Zoophytes, Polycistinse, Foraminifera, Parasites, and other slides in return. 



FRED. LEE CARTER, Gosforth, near Newcastle-on-Tyne, England. 

 Wanted, Diatomaceous earth from Megillanes, Bolivia, South America. Can give in exchange either Dia- 

 tomaceous earth from New Zealand or cash. E. MICHALEK, 



1. Fleischemarkt, No. i, Vienna, Austria. 

 Mounted sections of Foetal Lung (5 months), sections across entire lobe, irxjVs '"• thick, beautifully stained, in 

 exchange for first-Class pathological slides. W. C. BORDEN, M. D., U. S. A., 



Fort Douglas, Utah. 

 Wanted, earths, recent diatoms, and miscellaneous objects for mounting. Only first-class material oflFered or 

 desired. MARY A. BOOTH, Longmeadow, Mass. 



Fossil Diatomaceous deposits (marine) wanted from Bermuda, Virginia, Maryland, California, etc. 



L ELLIOTT, Ardwyn Villa. Aberystwith, Wales, England. 

 Labels for slides. EUGENE PINCKNEY, Dixon, 111. 



Correspondence relative to exchange in microscopical material or prepared mounts. 



HENRY L. OSBORN, Hamline, Minn. 

 First-class Histological Slides for other good mounts ; Histological and Pathological material cut on shares. 



S. G. SHANKS, M. D., 547 Clinton Ave., Albany, N. Y. 

 FOR EXCHANGE. — StrichniaChromate (Strichnia jjiigr.) andStrichnia Ferri-Cyanide (Strichnia i-Jog''-) 

 Will exchange for other slides. Botanical preferred. Only first-class slides offered or desired. 



L. A. HARDING, Fergus Falls, Minn. 



Notices. — All communications for publication should be addressed to Henry Leslie Osborn, Hamline 

 University, Hamline, Minn. 



Subscriptions, and all matters of business, should be addressed to Chas. W. Smiley, P. O. Box 630, 

 Washington. D. C. 



Subscription price $1.00 PER YEAR strictly in advance. All subscriptions should end with the De- 

 cember number. A pink wrapper indicates that the subscription has expired. A date on the wrapper in- 

 dicates the month to which payment has been made. 



Orders for slides advertised by A. J. Doherty in the Journals from January to April, 1887, may be sent 

 through P O. Box 630, Washington, D. C 



A few copies of Leidy's Fresh-Water Rhizopods, of North America, can still be had at $5 00 per copy. — P 

 O. Box 630, Washington, D. C. 



Remittances should be made by postal notes, money orders, or by money sent in registered letters. Drafts 

 should be made payable in Washington, New York, Boston, or Philadelphia. 



The first volume, 1880, is entirely out of print. The succeeding volumes will be sent by the publisher for 

 the following prices which are net: — Vol. II (18S1) complete, J1.50; Vol. Ill (1882), out of print ; Vol. IV 

 (1883) complete, $1.50; Vol. V (1884) complete, Ji. 50 ; Vol. V (1884), Nos. 2-12, Ji. 00 ; Vol. VI (1885), Jr. 50 : 

 Vol. VII (i886), $1.00; Vol. VIII (1887), $1.00. As calls for Volumes I and III sometimes occur, those persons 

 having copies to dispose of would do well to inform us, and to state their prices, 



