514 
Stegomyia fasciata 
After 60 hours the following had emerged: 
Peptone water ... ... 2 out of 16. 
0 „ 6 . 
Beef broth .all „ 18. 
4 „ 11. 
Peptone broth .1 „ 17. 
7 „ 17 
2 % solution yeast extract ... several*. 
Sterile. 
Infected. 
Sterile. 
Sterile; larva dead. 
>9 
3 % solution yeast extract ... 4 tubes, a few in each tube. 
It was noted that all the larvae in the yeast extract tubes containing charcoal 
were making progress, the dark line of their guts showing that the charcoal was 
being swallowed. 
After 84 hours: 
Peptone water 
.. 3 larvae from 16 
0 „ 6 
eggs. 
99 
Sterile; no progress. 
Beef broth 
.. all „ 18 
99 
Rapid progress of larvae; 
gas production by bac¬ 
terial growth. 
6 „ 11 
99 
Very sbght progress of 
larvae; still sterile. 
Peptone broth . 
. 1 larva (dead) 17 
99 
Sterile. 
9 larvae from 17 
99 
Very slight progress of 
larvae; still sterile. 
2 % solution yeast extract .. 
. 4 larvae from about 15. 
3 passed first moult. 
4 „ „ 
15. 
2 „ ,, 
3 % solution yeast extract ., 
•• 1 99 99 
15. 
Has p£issed first moult. 
4 
* 99 99 
15. 
Have „ 
3 ,, ,, 
15. 
1 has passed first moult. 
6 ,, ,, 
15. 
3 have passed first moult. 
With one exception the broth and peptone tubes passed out of the experiment 
owing to the larvae dying after a protracted period of minimal progress, or owing 
to sterility breaking down in the tubes, followed by the hatching of the dormant 
eggs and rapid development of the larvae. 
Beef broth. In one tube of beef broth sterility was maintained; on the 41s< day 
there were 4 bving larvae in the third instar; on the l&th day tests showed that the 
tube was still sterile, some of the larvae having advanced to the fourth instar. On 
the 90<A day 2 adults were reared; a small quantity of broth from the tube, together 
with one of the adult mosquitoes, was introduced into a tube of peptone broth which 
remained sterile. The original tube was infected with B. coli to see if any eggs 
were lying dormant; none hatched, so a few unsterlhzed eggs were added to test 
the nutritive properties of the broth after infection. Larvae emerged from the 
eggs the same day, by the 8th day nearly aU had passed the third moult. 
Yeast extract solution. Eggs were transferred after sterilization to a few tubes 
of 3 % solution of an autolyzed extract of brewers’ yeast; no charcoal being added, 
* The presence of animal charcoal in the tubes rendered an exact count impossible. 
