294 J. K. MURRAY. 
the time of cutting that the bacterial flora within the 
‘‘pasteurised’’ curd is much superior to that within the 
“raw.” 
These figures coupled with those obtained at renneting 
and cutting demonstrate that the flora of curd made from 
pasteurised milk is remarkably free from bacteria other 
than Streptococcus lactis, and that the living members of 
the harmful gas-producing group are few in number. As 
for killed members of this group, it is probable that the 
pasteurisation process destroys the endo-enzymes which 
dissociation of the dead cells during ripening might liberate. 
The first sentence of the preceding paragraph would not 
hold for milk pasteurised on farms—a practice being mis- 
takenly encouraged by at least one South Coast factory. 
Admittedly fast batches are thus reduced innumber. Farm 
pasteurisation entails the unevenness associated with as. 
many processes as there are farms. Many milks are over- 
heated with consequent changes in the milk solids, par- 
ticularly the casein and mineral content, which make for 
a cheese of unsatisfactory body and texture. Bacterial 
spores will survive the processes employed, germinate and 
produce undesirable products; the dangers of recontamina- 
tion are great. A uniformly high-grade product cannot be 
produced under such conditions. The practice should be 
compulsorily replaced by centralised pasteurisation at 
a factory. 
Reinfection of Pasteurised Milk. 
P. W. Allen'! found that pasteurisation caused milk to 
become more favourable to the attack of gas-forming bacilli 
and Bacillus cerogenes. While this weakened resistance 
is probably general for all common forms of milk bacteria, 
his investigations emphasise the necessity of minimising 
post-pasteurisation contamination. 

