BY A. JEFFEBIS TURNER, JI.D., LOND. 79 



have fallen close to each other on the plate, and that what 

 appears to be a single colony is really a mixed growth. In 

 the case of most of the organisms first cultivated from 

 apparently single colonies, I have had to avail myself sooner or 

 later of the method of isolation by gelatine plates ; and I now 

 always adopt this in the first instance. Though tedious, no 

 trouble is superfluous that assures the observer of the purity of 

 his cultures. The original colony is touched with a sterile 

 platinum wire, which is rinsed in a tube containing sterile 

 bouillon. A very minute platinum loopful of the bouillon is 

 then transferred to a tube of melted gelatine, which, 

 after gentle agitation, is poured out into a sterilised Petri dish, 

 where the separate colonies develop witlnn two or three days 

 and are utilised as the starting-point of pure cultures. 



I have here a number of pure cultures secured from the 

 Brisbane air of sixteen distinct species or varieties. It must 

 not be supposed that these are anywhere near the total number 

 of distinct forms that may be obtained in this locality by the 

 method I have described. I have preferred to concentrate my 

 attention in the first instance on a few forms, and more 

 particularly on those presenting some distinguishing feature, 

 such as the development of pigment. 



The first culture to which I draw attention is not a 

 bacterium at all, though indistinguishable in its method of 

 growth. It belongs to the group of torulse or yeasts, and 

 consists of comparatively large oval, often vacuolated, cells which 

 multiply by budding. The growths produced by it are of a 

 beautiful pink colour, and do not liquefy gelatine. It resembles, 

 and is probably identical with, a species of yeast organism 

 commonly found in an- cultivations in Europe. It has developed 

 rather frequently on my plates, where its conspicuous colour 

 readily attracts observation. 



The bacteria proper are represented in the first place by 

 eight different forms of cocci. These smallest forms of life 

 are exclusively found in the form of excessively minute spheres. 

 In the process of growth they divide into pairs, which, clinging 

 together, form what are known as diplococci. Three or five 

 cocci are not infrequently observed clinging together in chains. 

 Longer chains were not observed in the species shown. Some- 



