Saccharomyces anomalus [Hansen). 219 
cases they changed to such a degree as to look like small 
drops of brown jelly. In other cases they changed into flat 
circular milky-white colonies, much resembling solid drops of 
stearin, and recalling the appearance of streak-cultures on 
beer-wort gelatine (see Fig. 8). All these later changes are 
due to slight liquefaction of the gelatine, accompanied by 
either a soaking in of the beer-wort, or some oxidation. 
Plate-cultures made with dextrose-Mayer gelatine and 
saccharose-Mayer gelatine produce colonies of the same form 
as those in laevulose-Mayer gelatine. 
Saccharose , laevulose and dextrose gelatine (relying on the 
traces of mineral substance in gelatine in the absence of other 
inorganic salts) were also used as media for plate-cultures. The 
colonies on each were similar in form. They grow as dots 
to the size of about a pins head above the surface of the 
gelatine, but the growth is very slow, and then the formation 
of outgrowths like mycelia begins, and may continue until 
the central dot-like portion of the colony is surrounded by 
feathery radiations. See Fig. 6 showing colonies on sac¬ 
charose gelatine. 
General observations on colonies in plate-cultures. 
The form of the colony seems to be dependent on the 
temperature, the amount of moisture, the crowding of the 
Yeast-cells and their vigour, the consistency of the gelatine, 
and the nature of the food-material. Old colonies have a 
tendency to produce mycelium-like outgrowths at their edges. 
This matter would seem to be not without importance to 
the general question of the macroscopic appearance of colonies 
on plate-cultures. The typical form appears to be that of 
the raised, dry, chalky-white, brittle and even powdery 
wrinkled dome shown in the photograph (Figs. 1 and 7); but 
it is evident that any of the circumstances mentioned may so 
modify this that in extreme cases it would be difficult to 
recognize this organism from its plate-cultures. 
