K. E. Atkin and A. I^acot r)09 
During the same period in peptone water two larvae came out of 6 eggs in one 
tube only. 
Beef broth. Tube (No. 1), 1 out of 7 eggs 
„ (No. 2), 3 „ 7 „ 
„ (No. 3), 4 „ 7 „ 
Peptone broth. Tube (No. 1), 5 , 
„ (No. 2), 4 „ 
„ (No. 3), 2 ,, 
„ (No. 4), 2 , 
6 eggs (1 larva dead) 
The growth of the larvae was negligible. 
Three days later (5 days from start): 
Boiled tap ivater. None had hatched. 
Boiled distilled water. No progress by the larva. 
Peptone water. No further hatching; no progress by the larvae already hatched. 
Beef broth. Tube (No. 1), 5 hatehed out of 7. 
„ (No. 2), 6 „ „ 7. 
„ (No. 3), 4 „ „ 7. 
All the larvae were making slow progress. 
Peptone broth. Tube (No. 1), 5 hatched out of 6 (2 larvae dead); slight progress. 
„ (No. 2), 4 „ „ 6; slight progress. 
„ (No. 3), 2 „ „ 5; very slight progress. 
„ (No. 4), 2 „ „ 0; little, if any, progress. 
On the 8th day from start: 
Boiled distilled icater. Larva still in first instar. 
Peptone water. No change, the larvae still in first instar. 
Beef broth. A few more eggs had hatched; the numbers are now: 
Tube (No. 1), 6 hatched out of 7. 
„ (No. 2), 7 „ „ 7. 
„ (No. 3), 4 „ „ 7. 
All the larvae show slight growth, most of them being in the second iastar, but 
one has not passed its first moult. 
Peptone broth. The living larvae are now: 
Tube (No. 1), 4 out of 6 eggs. 
„ (No. 2), 4 „ 6 • „ 
,. (No. 3), 2 „ 5 „ 
„ (No. 4), 4 „ 6 „ 
Slight growth was apparent, but none had passed the first moult. 
On the 11th day from start: 
One of the peptone water tubes in which none of the eggs had hatched was 
inoculated with B. coli; by next morning (18 hours later) all the eggs in this tube 
had hatched. 
In tube No. 4 of the peptone broth tubes sterility had broken down, and there 
was a slight bacterial infection. In this tube only were the larvae making any 
progress; in aU the other peptone tubes the larvae were marking time. 
