TH E B A CTE R I A L N U C L K U S 53 



considerable attention. Robinow's description of the paired, chromosome- 

 like nuclear bodies was not the first to be made, but was the first to obtain 

 general credence. An easily available but little known paper by Paillot (1919) 

 shows the paired bodies clearly stained by Giemsa, and other examples might 

 be quoted. 



Observations were also made by ultra-violet light and by electron micro- 

 scopy which, it less striking in themselves, served to confirm those made by 

 the acid-Gicmsa technique. 



Another valuable staining method, the methylene-blue-eosin technique 

 was devised by Badian (1933) and used with success by subsequent workers. 



Two interesting studies were performed by a method of vital staining 

 with fuchsin, by Stoughton (1929, 1932) and Allen et al. (1939). These 

 papers stand rather apart from the main lines of discovery in this subject, 

 because, although they include observations ot great interest, fully substantiated 

 by photomicrographs, the cytological processes described arc unlike those 

 more commonly found, in some particulars. These papers will be discussed 

 in Chapters VI and VII. 



Claims have from time to time been made to demonstrate a classical 

 mitotic process in the bacterial nucleus, but these have never proved acceptable 

 to experienced bacterial cytologists. Almost without exception they have 

 been based upon an exceedingly small range of observations, and the most 

 recent (DeLamater and Mudd, 195 1 et scq.) has been supported by the constant 

 (unacknowledged) republication of a single " metaphase spindle," at different 

 magnifications, and sometimes inverted. This work has also been heavily 

 criticised upon technical grounds. 



B: THE RESTING NUCLEUS 



(2, 4, 5, 10, II, 12, 13, 18, 19, 20, 21, 25, 26, 27, 31, 32, 33, 34, 35, 36, 40, 41, 42, 47, 

 so, 52, 53, 59, 60) 



The bacterial nucleus, like those of other types o( cell, may appear in a 

 variety of different guises. It is probably even more protean than most, but 

 the changes of form which it undergoes are paralleled by similar processes 



