1891.] MICROSCOPICAL JOURNAL. 215 



many of the hitherto unknown problems of zoology. The remarkable 

 phenomena observed received their explanation in Darwin's theory of 

 descent, and are accounted for by heredity and variation. 



Much of this interesting paper was of a technical character, but its 

 various points and conclusions were well taken, and its delivery was 

 keenly appreciated. Dr. O'Toole exhibited various preparations by 

 the aid of the microscope, which served to elucidate points in his paper. 

 At the conclusion a unanimous vote of thanks was tendered him. 



G. O. Mitchell exhibited a recent gathering of pond water from 

 Mountain Lake, near the Marine Hospital, which contained thousands 

 of specimens of Volvox globator^ one of the most beautiful and inter- 

 esting of all fresh- water alg£e. This alg« is rare in this vicinity, and 

 search has been made for several years by our local observers without 

 success. Ten or twelve years since it was noted and shown at one of 

 the society's meetings by Colonel Kinne, but it was not until the pres- 

 ent time that its presence was again known. This only proves the 

 persistent recurrence of phenomena in nature, which have been ob- 

 served in both the animal and vegetable kingdoms. For a period of 

 years the absence of favorable conditions and environments seems to 

 completely obliterate certain forms, when suddenly their presence in 

 large numbers is noted. 



NOTICES OF BOOKS. 



Studies oit the Action of Dead Bacteria in the Living Body. Bv 

 T. Mitchell Prudden, M. D., and Eugene Hodenpyl, M. D. New 

 York, 1 89 1. D. Appleton & Co. (Reprint from N. T. Med. 

 Jour.') 



As often as once in five years a radical revolution takes place in the 

 Republic of Bacteriology. First, the Microbe was Dictator, then 

 Ptomaines and Leucomaines held a joint directory, and now Chemo- 

 taxis is nominated for president. 



Chemotaxis is the reaction, positive or negative, attractive or repel- 

 lent, between lowly, motile vegetable organisms and certain substances 

 that exert a chemical action on them. The motive of the first paper is 

 to insist that often too much attention is paid to the germ-cell, and too 

 little to the body-cell. 



The second paper is a record of experiments made by the authors to 

 determine the chemotactic power of dead tubercle bacilli when in- 

 jected into the cellular tissue, pleura, peritoneum, and veins of rabbits. 

 After these injections, the bacilli, still capable of being stained by the 

 ordinary methods, were found in various organs of the body, encap- 

 suled by nodules of newly-formed tissue closely resembling the miliary 

 tubercle. Aseptic, localized suppuration was produced. No living 

 bacilli were found, showing that the injected material had been 

 thoroughly sterilized. 



Similar experiments made witli the dead germs of several other dis- 

 eases failed to show any similar nodular growths, from which the au- 

 thors conclude that this power resides in and is peculiar to the bacte- 

 rior-protein of the tubercular bacillus. A wide range of possibilities 

 is suggested. The literary style of the articles is of a high grade. 



