Sl-X IN BACTERIA— E\IDENCE ERO.M iMORPIIOLOGY 35 



fixed, hydrolyzed, and stained by a method similar to that described 

 by Robinow (1942), one can find large bodies in which the chroma- 

 tinic material is in a compact mass (Fig. 28) and also those in which 

 the cliromatinic material is more distributed within the large body in 

 the form of granules, rods, or filaments (Figs. 29 to 31) (Stempen 

 and Hutchinson, 1951b), Any correlation between the results of the 

 two sets of observations must be considered suggestive only, for there 

 is no way of determining the mode of origin of the large bodies seen 

 in such stained films. 



Regardless of whether the large bodies arise by the fusion of two 

 rods or from a single rod, they may undergo the same type of con- 

 tinued development. The large body may divide into two; each half 

 then divides, and this process is continued until the normal rod form 

 is restored (Figs. 12 to 15). In the restoration of the rod form from 

 the large bodies of Streptobacilhis nwiiUi^onms (Dienes, 1943) and 

 Bacteroides strains (Dienes and Smith, 1944), the rods are reported to 

 occur preformed in the large bodies; and Dienes (1946) states that 

 the process in Proteus is similar to that in Bacteroides. 



On the other hand, large bodies of Proteus vidgaris OX- 19 may 

 develop in another way. The body ruptures; the contents appear as 

 a more or less homogeneous mass which is less refractile than the 

 body from which it arose. In a short time thereafter one or more 



Figs. 1 to 3. Formation of a large body by the swelling of a single rod. The 

 culture is IV^, 3%, and VA hours old (x 2000). 



Figs. 4 to 7. Formation of a large body by means of a lateral bud. The culture is 

 2, 2'/4, 2'/2, and 2% hours hours old (x 2000). 



Figs. 8 to 15. Fusion of two rods to form a large body with the subsequent 

 division of the large body to produce rods. The culture is 1, l'/>, H4, 2, 2%, 4, 6/4, 

 and 714 hours old (x 2000). 



Figs. 16 to 21. Fusion of two rods with the formation of a large body on one of 

 the pair of rods. The large body ruptures with the subsequent formation of a 

 microcolony of granular forms. The culture is 14, ^4, 1, Wi, IK, and 4 hours old 

 (X 2000).' 



Figs. 22 to 24. Production of granular forms following the rupture of a large 

 body and an adjacent rod (x 2000). 



Figs. 25 to 27. Production of granular forms associated with the outgrowth of 

 material from the large body. The large body later ruptures. The culture is 114, 2, 

 and 214 hours old (X 2000). 



Fig. 28. Large body with chromatinic material concentrated in a single mass 

 (X 3100). 



Figs. 29 and 30. Large bodies containing different amounts of chromatinic 

 material (X 3100). 



Fig. 31. Large body with chromatinic material in a filamentous form (X 3100). 



