E. E. Atkin and A. Bacot 
533 
No. of Tube 
B. coli ... ... ... No. 7, 4 larvae were living—all in third instar (prob¬ 
ably infected). 
No. 8, 3 larvae were living—all in third instar (cer¬ 
tainly infected). 
S. aureus ... .No. 9, 2 living larvae in third instar (certainly in¬ 
fected). 
No. 10, all dead in second instar (apparently still 
sterile). 
B. coli ... ... ... No. 11, all dead; at least 2 larvae gained their fourth 
instar. 
No. 12, all dead in second instar (apparently still 
sterile). 
B. coli ... ... ... No. 13, 4 larvae living in third instar; all the others 
died in this stage (probably infected). 
Filtrate ... ... ... No. 14, a number of living larvae all still in first 
instar (apparently still sterile). 
The history of the larvae was not continued beyond this point. 
As the effect of the addition of dead cultures of bacteria to the tubes in this 
experiment was so much at variance with previous trials and it seemed probable 
that the difference was due to some variation in the eggs, an endeavour was made 
to check these results in the following way: 
A small quantity of autolyzed yeeist and dead B. coli culture used in this experi¬ 
ment were therefore added to some tubes of distilled water taken from Experi¬ 
ment XXIII in which eggs had been lying dormant for 100 days. These tubes were 
numbered 4, 5 and 6. The fluids added were autolyzed yeast and B. coli which had 
been autoclaved, and a living culture of B. coli as control. 
To tube No. 4, about 3 % of living B. coli culture. 
,, No. 5 „ 3 % of sterile autolyzed yeast (autoclaved). 
„ No. 6 „ 3 % of sterile B. co/i culture (autochived). 
Result: 
No. 4, 1 egg hatched wi1 hin 2 minutes; 2 more within 5 minutes; 2 more 
within 10 minutes. 
No. 5, 1 egg hatched within 1:3—20 minutes. 
No. 6, 1 egg hatched within 15—20 minutes. 
After an hour and a half. 
No. 4, 8 out of 10 eggs had hatched. 
No. 5, 1 ,, 9 ,, ,, 
No. 6, 1 „ 11 „ 
These figures include the eggs hatched within the first 20 minutes. 
A small quantity of living yeast cells from a wort agar culture was then transferred 
by platinum loop to tube No. 5, the remaining eggs hatched within 15 minutes; all of 8. 
About 3 % of a living culture of B. coli, in broth, was added to tube No. 6; 
1 egg hatched within 3 minutes; another followed within 5 minutes and 4 more 
within 15 minutes = 6 out of 10. 
The failure of 4 eggs to hatch was probably due to their being dead. 
35—2 
