[HARRISON] VISCOUS FERMENTATION OF MILK AND BEER 81 



part either grew gradually or quickly into the bright, shiny, greyish 

 edge, but colonies of the same culture behaved inconsistently in this 

 respect. At times radiate lines appeared at the edge and occasionally 

 extended to the centre of the colony. The colonies did not, as a rule, 

 develop viscosity until they had reached a certain size. The degree 

 of viscosity varied in colonies on the same plate, made from the same 

 culture; some developed "\dscosity to a limited extent, more rarely none 

 developed, whilst others were so viscous that they could only be removed 

 in toto. 



Microscopical appearance of colonies. — Very young colonies were 

 grey, irregular and more or less granular, later the centre turned dark, 

 and finally became opaque, the margin alone remained transparent and 

 granular. The centre portion gradually or quickly grew towards the 

 edge of the colony. Colonies of varieties 1, 3 and 5 showed radiate, 

 dark markings at the edge, but these markings did not extend to the 

 centre. Deep colonies were pimctifortn in shape, yellow-brown in colour, 

 granular when young, with dark radiate markings in varieties 2 and 3, 

 later they became opaque. 



Gelatine sticli cultures. — At the surface of the point of inoculation 

 a good growth formed which resembled a surface gelatine colony. The 

 centre was prominent, shiny, but later became dull grey or bro\\Ti. This 

 growth spread slowly or quickly into a thin, shiny, grey, smooth expan- 

 sion. The edges were slightly lobulate. 



A fair growth developed along the line of inoculation, more abun- 

 dant near the surface than deeper in the gelatine. The growth appeared 

 as a fine granular white line; with age, the granules became larger, 

 more opaque, and in variety 3, a homogeneous confluent growth occurred. 

 Arborescent growth might take place, and this brush-like growth was 

 either along the whole line (varieties 2 and 5) or only at some places 

 (1 and 4) ; this feature of growth Avas not constant, the gelatine never 

 became liquefied, but after one or several weeks, the gelatine next to 

 the stab became turbid. 



Gelatine streah cultures at 20° C. — A shiny, smooth growth ap- 

 peared along the line of inoculation in 24 hours. The growth spread 

 rapidly and the edge became irregular, denticular or lobulate. The 

 growth was shiny, smooth and more or less arborescent, the centre 

 became raised, at first shiny, but later dull with furrow-like markings. 

 The centre gradually grew toward the edge. The cultures were viscid. 



Agar plate and streak cultures. — Were like the corresponding gela- 

 tine cultures, but with less marked features. The condensation water 

 of the sloped tubes became turbid after 24 hours and was very viscid, 



Sec. IV., 1905. 6. 



