172 C.-E. A. WiNSLOw AND Anne F. Rogers 



Supplementary tests. — Many other tests than those mentioned 

 are sometimes used in bacterial diagnosis, but none have seemed 

 suited to the present study. The questions of pathogenicity and 

 agglutinative power are so shrouded in confusion as to be unprom- 

 ising. Meyer (1902) considered serum reactions of diagnostic 

 value among the streptococci, and Kolle and Otto (1902), and Otto 

 (1903), obtained good results with the staphylococci. On the other 

 hand, Aronson (1903), Fischer (1904), and Kerner (1905), after 

 very thorough investigations, came to the conclusion that these prop- 

 erties among the streptococci are so erratic as to be quite valueless 

 in systematic work. From a general survey of the literature of the 

 group, it seems probable that the properties connected with infection 

 and immunity are hkely to be too easily modified to prove helpful 

 in classification. 



The test for Mquefaction of starch is one which it seems logical 

 to include with those which show the relation of an organism to 

 gelatin and the sugars; and we made some experiments with the 

 starch media introduced by Smith (1905). It appeared that cer- 

 tain cocci did exert an amylolytic action and the study of this char- 

 acter would probably prove of considerable interest. It has been 

 omitted for the present, for lack of time. 



III. RESULTS OF THE INVESTIGATION. 



The characters observed and the terms in which they are record- 

 ed may be summarized as follows : 



1. Habitat. — Recorded as i (diseased conditions); 2 (normal 

 body); 3 (water); 4 (earth); or 5 (air). The significance of these 

 various habitats has been more fully discussed above. It should 

 be noted that Group 5 includes certain laboratory cultures whose 

 origin was unknown. 



2. Grouping of cells and dimensions. — Observed in stained prepara- 

 tions, made from 20° agar cultures less than five days old. Group- 

 ing recorded as i (packets present); or 2 (packets not present). 

 Extreme dimensions recorded in micromillimeters to the nearest 

 loth. 



3. Relation to Gram stain. — Observed on two occasions on 20° 

 agar cultures less than five days old. Treated with anihn-oil-gentian- 



