522 
Stegomyia fasciata 
No. 5, the mould in this tube was more vigorous; it formed flocculent tufts just 
beneath the surface. The last larva to die was in its third instar. None lived 
beyond 50 days. 
No. 6, white surface moulds grew gradually; 3 larvae were Uving on the 53rd 
day; the last survivor died in the third instar within 60 days. 
No. 7, in addition to floating moulds, this tube had a heavy bacterial growth 
in it. 2 fourth instar and 1 second instar larvae were hving on the 69th day, but aU 
died without reaching pupal stage. 
No. 8, small globular moulds developed at the bottom of the tube; aU the larvae 
died in the first or second instar early in the course of the experiment. 
No. 9, this tube had an obvious infection, a surface scum formed, but there 
was no trace of masses of mould, as in the other tubes; 5 larvae fingered in the 
second and third instars until the 53rd day, but all died out by the 69th. 
Beef broth and water. 
No. 1, a white surface mould; all larvae died in first and second skin. 
No. 2, a weak, double bacterial infection; larval progress slight; several larvae 
in second and third skin were living on 53rd day; by the 106th day 1 larva was 
still living and a sub-culture in broth gave no result, the infection being presumably 
too slight. 1 c.c. of broth was added to the tube and subsequently -5 c.c. from the 
tube was added to sub-culture broth tube. Result: infected. A larva hatched 
from a dormant egg within two hours of the addition of broth, presumably as the 
result of increased bacterial growth consequent upon the addition of fresh nutritive 
material. 
No. 3, this tube remained sterile to aU the tests appfied; 1 larva reached second 
and 1 the third skin by the 53rd day; both died subsequently. 
No. 4, this tube remained sterile; 5 larvae were still living in the first instar on 
the 21st day; on the 28th day the larvae showed little if any progress. A mass 
of living yeast cells {S. cerevisiae), lifted from a wort agar slope, was added to the 
tube; several dormant eggs hatched within a few minutes. The larvae all grew 
rapidly and cleared the water, which became cloudy when the yeast cells were 
introduced, within 5 days. A fresh loopful of the yeast cells was added. In 
2 days’ time the water was again clear, and a fresh loopful was given. On 
the 13th day most of the larvae were in their fourth skin and one had pupated. 
Another loopful of the yeast cells was given. A week later a male was reared and 
a loopful of yeast cells added. A second adult, a $, was reared on the 25th day 
after infection. A further loopful of the yeast cells was given; by the 32nd 
day 3 adults had been reared. There were L pupae and 4 fully developed 
larvae; further yeast cells were given. In all 8 adults were reared in 40 days. 
The period taken in this instance was due to the lapse of time between the meals 
and the small allowance of food given at any one time; had a larger mass been given, 
not above one-third of the time would have been taken. 
No. 5, several very small moulds grew at the bottom of the tube. The larvae 
made slight progress; the moulds did not develop, and apparently died out. The 
larvae made very slight progress, but by the 40th day after hatching none had passed 
the second instar. Some of the larvae died, others made slow progress. After 
100 days there were 2 living, 1 in the third and 1 in the fourth instar. Tested 
and found sterile on the 100th day. 
