( 671 ) 
the case as soon as from those compounds acids are formed, as wil 
be shown below. 
When considering attentively the decomposed portions of the cul- 
ture plates we observe that around each white central part of a field, 
consisting of fatty acid, soap, and compounds of lipase with fatty 
acid, a less white band extends formed from fatty acids. Around 
this less white part another band is found characterised by still 
more clearness, it is even more transparent than the non-decom- 
posed adjoining fat. This clear portion is formed in consequence 
of the disappearance of the fat-crystals, caused by the lipase action. 
These bands are very well seen in the figure; on the culture 
plates themselves they can be distinguished still better. 
The same is observed respecting little staves of fat placed in a 
lipase solution. Fig. 1,2 and 3 Pl. 4 are drawings (24 times magnified) 
of pieces of dry fat kept for 30 days at 20° C. in test tubes of broth 
inoculated with fat-splitting microbes. On the outside of the fat (in 
the figure at the top) is a bacterial film under which a white sa- 
ponaceous part (on the plate cross-hatched) then a layer consisting 
of fatty acids (hatched), and finally the non-deeomposed fat. 
The diffusion velocity of lipase in dry fat is, as the experiment 
shows, very small. In one month the lipase has penetrated into 
the fat not more than half a millimeter. In moist fat that velocity 
is much greater. The great difficulty however, evenly to emulsionate 
water and fat, makes comparative experiments as to the diffusion 
velocity of lipase in fat containing different quantities of water 
almost impossible. 
As said above, the rate of acidity of the medium influences the 
degree of decomposition of fat by fat-splitting microbes. When using 
an acid culture agar for the lipase reaction after EYKMAN we see 
under and around the bacterial inoculation streaks in the fat layer 
a wide field appear, but we do not perceive a white central part 
as is the case when the plate is alkaline. 
From a series of experiments which will be discussed in a separate 
communication, followed that for some micro-organisms two lipases 
are formed which, besides by their different diffusion velocity, are 
also characterised by. their different behaviour towards acids. 
Thus, B. Stutzert and B lipotyticum secrete two lipases, «-lipase 
and g-lipase; the former diffuses more rapidly than the latter and 
splits fat as well in an acid as in an alkaline medium. 
B-Lipase is formed in an acid medium, but does not decompose 
fat in it, it may however, become active again after neutralisation 
of the medium. 
