74 



CULTIVATION OF AEROBIC MICRO-ORGANISMS 



D. In the case of stab cultures in gelatin, note : 



1. The mode of growth. 



The following appearances are observed with different species : 



(a) A straight line along the line of sowing (fig. 59). 



T 



FIG. 59. Rectilineal growth. FIG. 61. Arborescent growth. 



FIG. 60. Tylotate growth. FIG. 62. Surface growth. 



Stab cultures in gelatin without liquefaction. 



(b) Growth in the form of a nail, which may be abundant or scanty, and 

 more or less marked at the head of the nail (fig. 60). 



(c) An arborescent, ramifying growth (fig. 61). 



(d) A growth strictly limited to the surface (fig. 62). 

 2. Whether liquefaction occurs ; if so, note : 



(a) The time when it is first observed. 



(b) The form which the liquefaction takes, whether it be cylindrical, funnel- 



FIG. 63. Cup-shaped liquefaction. FIG. 65. Glove finger liquefaction. 



FIG. 64. Funnel-shaped liquefaction. FIG. 66. Cylindrical liquefaction. 



Gelatin stab cultures with liquefaction. 



shaped, in the form of a glove finger or of a small cup (figs. 63 to 66). 

 if an air bubble appears at the top of the growth. 



Note 



