200 



THE AMERICAN MONTHLY [October, 1883. 



bercle, with the single exception that at 

 the center of each granulation was found 

 the microscopic egg of a nematode worm. 

 And in the disease under consideration 

 we have another variety of tubercle that 

 seems to differ only in that the center of 

 each granulation consists of a tuft of the 

 actinomyces fungus. It seems probable, 

 therefore, that what has heretofore been 

 looked upon as a single disease may be 

 divisible into a number of distinct dis- 

 eases, and that this may prove to be a 

 partial explanation of the discrepancies in 

 the results of different investigators. 



Since this organism multiplies locally it 

 is evident that, as a rule, it gains entrance 

 to the body near the seat of the resulting 

 disease. A slight wound, an abrasion, a 

 scratch, even, may be sufficient for its 

 lodgement ; while it seems probable that 

 it may, at least in certain cases, vegetate 

 on the moist mucous membrane, even 

 when uninjured, and send its myceliuminto 

 the tissues beneath, there to produce the 

 disease in all its intensity. The tubercles 

 of the lungs seem to be the result of the 

 vegetation of spores that have been in- 

 spired with the air. And it is not unlikely 

 that the germs which cause the lesions of 

 various parts of the digestive tract find 

 their way to the mouth in the same man- 

 ner. 



NOTICES OF BOOKS. 



Photo-Micrographs and How to Make 

 Them. Illustrated by forty-seven photo- 

 graphs of Microscopic Objects, Photo- 

 Micrographs Reproduced l^y the Helio- 

 type Process. By George M. Stern- 

 berg, M. D., F. R. M. S., Major and 

 Surgeon U. S. A., etc., etc. Boston: 

 Jas. R. Osgood & Co., 1883. (8vo., pp. 

 204, cloth, $3.00.) 



Dr. Sternberg has given in this volume 

 a very clear, concise and complete descrip- 

 tion of his method of making photo-mi- 

 crographs, in which he has achieved very 

 great success. He has divided the book 

 into two sections, the first of which treats 

 of the " Technology " of the subject, re- 

 lating to Light, Microscopical Apparatus, 

 Camera and Photographic Material, Ar- 

 rangement of Microscope and Camera, 

 Operating Room, Focussing, Exposure, 

 Development and Preservation of Nega- 

 tives, Photographing by Reflected Light, 

 making of Positives upon glass, and the 



Selection and Preparation of Objects. 

 The second part contains a description of 

 the plates and occupies nearly one-half of 

 the book. The plates contain the follow- 

 ing figures : Aina'ba.. micrococci, unicellu- 

 lar algae, Euglena ■z/Zr/rZ/j", spores of fungi, 

 epithelium cells, scales of insects, blood- 

 corpuscles, pollen-grains, epidermis of 

 plants, plant-hairs, sections of vegetable 

 tissues, five plates of diatoms including a 

 handsome photograph of the fourth 

 square of Moller's " Diatomaceen Tv- 

 pen-Platte" X 50, sections of animal tis- 

 sues, parasites, teeth of mollusca, tracheae 

 of insects. 



The book is handsomely printed in 

 large type, on heavy paper, and well- 

 bound. We reserve some further refer- 

 ences to this useful book for a future 



Exchanges. 



For Exchange. — First class double-stained sections 

 of Magnolia, Fig, Orange, Oleander, Butter-nut, Birch 

 arid many others: also fine injected specimens. N. A. 

 Richards, St. Louis, Mich. 



For Exch\nge. — Slides of pollen of pitch pine, 

 Pinus rigida, with the connection stained, for any 

 named slides of algae. Dr. C. F. Millspaugh, E. M. 

 S., Binghampton, N. Y. 



Wanted. — Trichina Spiralis, Pleurosigma Ang., or 

 other well-mounted slides in exchange for fine slides. 

 Insects, Acari, Spermatozoa of Horse, Physiological 

 and Pathological preparations. J. O. Stillson, M. D., 

 504 Upper Second Street, Evansville, Ind. 



Well-mounted slides of Polycystina, transparent and 

 opaque, for any well-mounted slide. P. C. Cole, M.D., 

 254 West Forty-second Street, New York, N. Y. 



Wanted. — Slides of Bacteria in exchange for other 

 slides, or for cash. J. M. Adams, Watertown, N. Y. 



Wanted. — I will give a good type slide of diatoms, 

 or a slide of arranged diatoms, for a gathering of Pleuro- 

 sigma (ingulatum. Thos. Christian, io8 Virginia St., 

 Richmond, Va. 



Fo-siL Diatoms from Carson, Nev., and f'osa Creek, 

 Cal., slides or material to exchange for good diatoms, 

 mounted or material. Also, many other diatoms; lists 

 exchanged. The above deposits are rich and newly dis- 

 covered by myself. F. H. Engels, M.D., Virginia, Nev. 



