112 



THE BACTERIOPHAGE AND ITS BEHAVIOR 



Tests 1 to 4 were made in bouillon; 5 to 7 were made in physiological saline, 

 gr. = bacterial growth. 



In view of these results it would seem that we must assume that a 

 true chemotactic influence is operative in the behavior of the bacterio- 

 phage corpuscle.* 



3. PENETRATION OF THE CORPUSCLE INTO THE BACTERIUM 



With the bacteriophage fixed to the bacterium, does it remain ad- 

 herent to the surface or does it penetrate to the interior of the cell? 

 "Macroscopic" experiments are inadequate to determine this point, 

 but "microscopic" observation, chiefly by means of the dark-field 

 method, provides some information. 



Inoculate 0.1 cc. of a very active Shiga-bacteriophage suspension into 

 10 cc. of a suspension of 250 milfion Shiga bacilU per cubic centimeter. 

 During the period when bacterial dissolution is taking place most 

 vigorously remove a drop of the suspension and examine it under the 

 dark-field. Not a single bacterium will be seen which appears to be 

 undergoing disintegrative changes. The only visible abnormality is 

 that in the midst of the normally appearing bacteria some few will 

 be seen presenting an "inflated" form. Those departing farthest 

 from the typical cell are completely spherical, with a diameter of 3 to 



* In this preliminary note, adequate however to allow of a decision, Kabelik 

 announces the publication of a more extended memoir on the question. 



