The Character of the Flagella 357 



of their flagella. To complete the comparison the number of 

 flagella on 200 germs is recorded. Of these, 10 had no 

 flagella, 33 had one, 33 had two, 45 had three, 38 had four, 19 

 had five, 6 had six, 8 had seven, 6 had eight ; and 2 had nine. 

 The longest flagellum observed measured 1 1 ft. The usual 

 (about 75 percent.) length was from 6 to 8/*. The small 

 circles at the distal ends were also present but in small num- 

 bers. 



Flagella on Bacillus coli communis. (Plate i. Fig. 2). A 

 culture of the bacillus coli communis, obtained by Dr. Theo- 

 bald Smith from the human intestine. A microscopical ex- 

 amination of a hanging drop preparation from an agar culture 

 of this species showed comparatively few of the germs to be in 

 motion. Upon watching it carefully for several minutes, 

 many of the individual germs which were first at rest ex- 

 hibited an active motility. 



The diameter and arrangement of the flagella on this species 

 do not differ to any appreciable degree from those on the hog 

 cholera bacteria. The number of filaments on the individual 

 germs varied considerably. Seven was the maximum number 

 found on a single organism. As before, an actual count of 

 the flagella on 200 individual germs selected from representa- 

 tive fields was made. Of these, 9 exhibited no motile ap- 

 pendages, 33 had one, 58 had two, 44 had three, 34 had four, 

 15 had five, 4 had six and 3 had seven. The number of the 

 free flagella in many of the fields averaged about one to each 

 germ. This is unimportant as in other parts of the prepara- 

 tions the number was greater and in still others less. The 

 length of the filaments varied from 2 to 12 /x. The greatest 

 number (66 per cent, of a large number measured) were from 

 5 to 7 /x. It is of interest to note that the number of individual 

 bacteria which exhibited no flagella was no larger in this 

 species than in the preparations of the hog cholera bacteria 

 where apparently every germ was actively motile. A very 

 few of the flagella formed nearly or quite perfect circles or 

 rings at their distal ends. Their existence, even in small 

 numbers eliminates their specific value when compared with 

 hog cholera and typhoid bacteria. 



