100 



THE AMERICAN MONTHLY 



[May, 



Prof. Edward Burgess showed several 

 water fleas having upon their carapaces 

 masses of Oscillaria, and also colonies 

 of rotifers upon their upper and under 

 surfaces. 



E. A. Balloch, Rec. Sccr. 



San Francisco, Cal. 



Meeting held April 14th. 



Dr. Henry Ferrer showed several slides 

 containing the living, actively moving 

 germs of typhoid fever. He prefaced the 

 exhibition by giving a shore resume of 

 what is known regarding these interest- 

 ing organisms. Many attempts have been 

 made for a number of years past to detect, 

 in the tissues of typhoid fever patients, 

 some micro-organisms to whose presence 

 could be ascribed the cause of the disease, 

 but it was not until 1880 that Eberth of 

 Halle succeeded in attaining a measura- 

 ble degree of success in this direction. 

 He found in the spleen, and infiltrated 

 lymphatic glands of typhoid fever patients, 

 a short thick bacillus with rounded ends. 

 Koch had previously found the same or- 

 ganism /;/ situ in the tissues, and had ob- 

 tained photographs thereof, but had not 

 published his discovery. Eberth at first 

 supposed that the bacillus of typhoid could 

 not be stained, or only with great difficul- 

 ty, but Koch, while corroborating many 

 of Eberth's researches, pointed out various 

 methods by which the staining could be 

 effected, notably with Bismarck brown 

 and with vcsuvin. The Koch - Eberth 

 bacillus, as it is now commonly called, 

 forms endogenous spores at a temperature 

 of 30° to 40° centigrade, and these spores 

 do not take the stain in which the bacil- 

 lus may be immersed. A noteworthy 

 fact in connection with these bacilli is 

 the formation of long threads, which 

 were erroneously considered to be distinct 

 organisms by some of the earlier ob- 

 servers, until Koch showed them to be 

 secondary forms of the typhoid bacillus. 

 Treatment with acetic acid distinctly re- 

 veals segments in the threads, and at these 

 points the living organisms eventually 

 break up into individual bacilli. Proba- 

 bly the most distinctive characteristic of 

 the typhoid bacilli is the method of 

 growth in gelatin and other similar 

 media. When a tube containing steril- 

 ized peptone gelatin is inoculated with a 

 pure culture of the organism in question, 

 the latter does not liquefy the culture 

 medium, neither do its growing colonies 

 form around the puncture made by the 

 inoculating needle, but they grow entirely 



at the surface of the gelatin, forming a 

 dense grayish white layer there. 



Dr. Ferrer's remarks were illustrated 

 by blackboard diagrams, and in conclu- 

 sion he showed the living bacilli, in va- 

 rious stages of growth under, two fine 

 ' Zeiss ' microscopes, using that maker's 

 ' F ' objectives. 



Mr. Wickson exhibited a slide of Trich- 

 ina spiralis, sent him by Dr. W. S. Tay- 

 lor, of Livermore, from a fatal case of 

 trichinosis which occurred in that town 

 last week. 



The paper of the evening was read by 

 H. (1. Hanks, his subject being ' The So- 

 called Inyo Marble, and California Build- 

 ing Stones in General.' 



A. H. Breckenfeld, Rec. Seer. 



NOTICES OF BOOKS. 



Biological Teaching in Colleges . 

 By William G. Farlow, Professor of 

 Cryptogamic Botany, Harvard Uni- 

 versity. (Svo pamphlet, pp. 10). 



An interesting article, particularly to 

 those who are giving attention to the 

 methods of education and their results ; 

 reprinted from The Popular Science 

 Monthly. 



How to Photograph Microscopic Objects. 

 A Manual for the Practical Microscop- 

 ist. By J. H. Jennings. New York: 

 E. & H. T. Anthony «& Co., publish- 

 ers. (8vo., pp. 32.) 



This is a concisely-written brochure, 

 eminently practical, and a reliable guide 

 for the amateur in this work. The pub- 

 lishers, however, need not have gone to 

 England for a competent author of such 

 a work, and a book especially written for 

 American microscopists would undoubt- 

 edly have more reference to American 

 apparatus than this one has ; indeed we 

 have not met with a single reference to ' 

 an American microscope or accessory in 

 it. However, this is the only small work 

 we can now call to mind treating particu- 

 larly of this subject, and as the informa- 

 tion and instruction it gives are good and 

 practical, we are glad to commend it to 

 beginners in photo-micrography. 



On KocJis Methods of Studying the Bac- 

 teria, with Special Reference to the 

 Bacteria causing Asiatic Cholera. By 

 T. Mitchell Prudden, M. D. (Pam- 

 phlet, pp. 18). 

 From the Report of the Connecticut 



State Board of Health for 1885. 



