76 IOWA ACADEMY OF SCIENCES. 



isolated twenty-eight species of this genus. Five of them are pathogenic to 

 common mice.-"" Many of these Streptococci are not, however, pyogenic. 



Ever since Ogston, Rosenbach and Passet demonstrated the presence of Staph- 

 ylococci and Streptococci in pus, it has been universally held that they had some 

 causal relation to the formation of pus. But, it is also a well established fact that 

 pas may be formed without germs as was first demonstrated by Grawitz and later 

 by Scheurlen and others. The aseptic introduction of turpentine, nitrate of silver, 

 and sterilized pus cultures under the skin will give rise to pus. That certain other 

 pathogenic bacilli and some saprophytic bacteria when sterilized can cause the 

 formation of pus seems also to be reasonably well demonstrated. So universally 

 are these pyogenic micro-organisms distributed that unless the greatest precautions 

 are taken, they gain entrance to the wound and, the surgeon finds his patient not 

 recovering as rapidly as he should. These pus organisms have a low thermal death 

 point. The Streptococcus pi/ogenes*^, 52-57.4° C. 



Staphi/lococcus pyogenes var. aiireusis according to Sternberg is killed at 56° C, 

 but Mr. Wade found in the writer's laboratory that it is somewhat higher, perhaps 

 a different race'^^^ 'pjjjg jg ^ relatively low thermal death point since many 

 species especially the anthrax bacillus produce resistent spores which stand 

 100° C. for several minutes. Some of the germs commonly found in the air like 

 Sarcina lutea which do not form spores are only destroyed above 70''^ C. when heated 

 for ten minutes. 



There are few diseases which have awakened a deeper interest than tuberculosis 

 in man and lower animals. The announcement of the discovery of the Bacillus 

 was made by Koch*'' in 1832 and independently, about the same time, Baum- 

 garten*'^ discovered a specific Bacillus as the cause of tuberculosis. Villemin'" as 

 early as 1866 had shown that tuberculosis might be induced in healthy animals by 

 innoculation of tuberculous material. These results were later confirmed by Cohn- 

 heim,*" Salomonsen** and others. Baumg^-rten and Koch demonstrated the ident- 

 ity of tuberculosis in bovine animals and man. Later it was shown by Ernst and 

 otherb*' that milk from tuberculosis animals was infectious. 



There was much hesitancy at first to accept the conclusions of Koch in regard 

 to the infectious nature of tuberculosis, for the theory that tuberculosis was an 



lOVeranus A. Moore in a paper on Miscellaneous Investigations concerning Infec- 

 tious and Parasitic Diseases of Domesticated animals. Bulletin No. 3, Bureau of Ani- 

 mal Industry, U. S. Dept. of Agriculture, pp. 9-30, gives an interesting account of the 

 biology of some of thiese Streptecocei and also refers to tiie work of Smith, Salmon, 

 Rosenbach and others. 



"Sternberg's Manual of Bacteriology, p, 274. 



42]. c. p. 267. 



43lt is possible that in this species as in Bacillus pyocyaneus there are different races 

 as has been shown by several investigators. 



WDie AetiologiederTuberculose, Berlin Klinische Wochenschrift, 1882, No. 5. 



45See Baumgarten Lehrbuch der Pathologischen Mykologie Vorlesungen f ur Aerzte 

 und Studirende, Harold Bruhn, Braunschweig, pp. 973 with 100 figures. See page 535. 



4«Etude sur la tuberculose, Paris, 1868. 



i^Uebertragberkeit der Tuberculose, Berlin, 1877. 



48How far may a cow be tuberculous before her milk becomes dangerous as an 

 article of food, Hatch. Experiment Station Mass. Agricultural College Bulletin No. 8, 

 April, 1890, Bang. Proc. Inter-nat. Medical Congress, Copenhagen, Vol. I., Path. 

 Sect. p. II. 1884. McFadeyean and Woodhead, see Woodhead, Bacteria and their Pro- 

 ducts, p. 224. 



Smith & Schroeder, Bull. No. 3, Bureau of Animal Industry, U. S. Dept. of Agri- 

 culture. 



A contribution to the question of the danger of infection with tuberculosis through 

 ordinary milk. The Journal of Comp. Path, and Therap., Vol. VI, p. 97. 



