58 MICRO-ORGANISMS AND DISEASE. [CHAP. 



new elements of successive divisions may remain connected, 

 and thus form a chain (or mycothrix, Itzigsohn and Hallier ; 

 torulaform string, Cohn), or they separate into single 

 organisms or dumb-bells. In some species there is a 

 pre-eminent tendency to form chiefly dumb-bells, in 

 others to form shorter or longer chains generally more 

 or less curved, streptococcus (Billroth). 



Such exquisite chains one meets with sometimes in serum 

 of blood exposed to the air for some days, and in pleural and 



. 



A ' 



. x. n 



..... **: 



FIG. ii. MICROCOCCI OF PUTRID 



HUMAN SPUTUM. 



1. Single micrococci and dumb-bells. 



2. Short chains. 



3. A long chain. 



4. A zooglcea. 



This and all subsequent figures are 

 drawn under a magnifying power of 

 about 700 diameters except stated other- 

 wise. 



is 



V 



FIG. 12. FROM THE SAME PUTRID 

 SPUTUM AS IN PREVIOUS FIGURE. 

 THE MICROCOCCI ARE LARGER. 



1. Dumb-bells. 



2. Sarcinae. 



3. A small zoogloea, in reality consisting 



of four sarcina-groups. 



peritoneal exudations of animals dead for a few days. 1 

 have seen in an artificial culture made by my friend Mr. A. 

 Lingard from a blister in a rabbit's ear the most exquisite 

 convolutions of threads of micrococci. (See Fig. 13.) 



A dumb-bell is also called a diplococcus (Billroth). 

 Between the individuals of a dumb-bell there is always 

 noticeable a short pale intervening bridge. 



