NUTRIENT JELLY IN TEST-TUBES. 



83 



of liquefying it ; others produce nodules, delicate or thick cloud- 

 masses, spicular or branched growths ; others have a distinct colour 

 reaction, by which they may at once be recognised (Figs. 35 and 36), 

 and the same holds true with regard to odours characteristic of certain 

 species. But this last feature avails but little in differentiating species 



Fig. 38. — Cultivation in nutrient jelly of micrococcus found in 

 osteo-myelitis. 



a. Liquefied upper layer. 



b. Sediment from liquefied portion, forming an orange-yellow 



mass of micrococci. 



c . Growths of the micrococcus along the tracks of the needle. 



generally, as a classification of odours on a scientific basis is still a de- 

 sideratum in many branches of biological research. 



