1018 SUMMARY OF CURRENT RESEARCHES RELATINQ TO 



Rwollings pick up coloitr readily, consequently tlicy arc not spores. 

 Unlike most vibrios, this one is well stained by (Jram's method. It does 

 not liquefy gelatin, but on plates forms cliaracteristic colonies of a dirty 

 wliito colour, which, in a few days, attain a diameter of 0"3-0-5 mm. 

 It is apparently not pathogenic. 



Vibrios from canal mud. — The primary fact connected with these 

 organisms appears to be that ceitain of them are antagonistic to others ; 

 that is, an examination of the canal mud showed various microbes, some 

 of which, when the original material was sown on gelatin jilates, were 

 found to disappear. One kind which is very constant is " hay vibrio," 

 and as it would seem to liave some connection with rotting substances, 

 the author proposes to alter its cognomen to Vibrio sap-ojihilcs a. Ilay 

 vibrio ^ might then be renamed Vibrio sapropliiles (S. A third form 

 of this class of vibrio, F. sapropliiles y, morphologically resembles 

 V. saprophiles a, but it is of larger dimensions, and has rounded ends. 

 Ono jjeculiarity is its tendency to produce abnormal forms, especially in 

 old cultures, and another is the possession of round or oval spaces which 

 are uustainable. 



On gelatin-plates the deeper colonies, macroscopically white, attain 

 the diameter of 1/2 mm. in a week. Under a low power the centre of 

 the colony is orange, and the sliarply defined margin yellow. The more 

 superficial colonies are less regular. On potato they show a striking 

 inconstancy, although the cultivations arc quite pure. 



Vibrios which grow with a yellow colour. — On gelatin plates it is 

 noticeable that from canal mud vibrio- colonies frequently appear with 

 a yellow colour. These are morphologically identical, and one descrip- 

 tion serves for all. They exhibit an extraordinary variety in their 

 growth and form in the same and in different cultivations. Their only 

 constant is their thickness, which is about half that of the cholc^ra 

 vibrio. Degeneration-forms are also found in artificial media. These 

 are characterized by the irregularity of their shape, that is, irregular as to 

 the recognized form of a vibrio. Although morphologically alike, the 

 author finds it necessary to make three varieties of these yellow vibrios, 

 namely Vibrio aureus, jiavus, and flavescens, between which the differ- 

 ences seem comi)aratively trivial. 



The author then proceeds to impart some general considerations on 

 the morphology and biology of vibrios. A vibrio is defined to be a bent 

 rod twisted about its long axis. The degree of bending and torsion, and 

 the relation between the two, determine the shape of the screw, and to 

 all bacteria which, either singly or collectively, are developed with 

 this torsion, the author would give the name of Vibrio. 



With regard to spore-formation in vibrios, the author is of opinion 

 that true spore-formation has never been hitherto demonsti-ated. It is, 

 however, probable, that in the saprojihilous vibrios, the formation of 

 resting forms does occur. 



Many vibrios show in liquid media characteristic movements, and 

 this is associated with the necessity for oxygen, in which the yellow 

 varieties thrive best. 



The part which the author assigns to decomposition vibrios — is, not 

 that of exciting the process, but rather of destroying its results, namely 

 those matters which act harmfully on animal organisms. 



Many vibrios possess the power of developing in very dilute nutrient 

 media and of successfully competing therein with other bacteria. 



