526 
Stegomyia fasciata 
After 28 days. 
Distilled water. No change; eggs still dormant. 
Distilled water and Filtrate. Nos. 9 and 10, the larvae still marking time. 
No. 11, another adult reared; some of the larvae have died, only 1 is now 
living. 
No, 12, only 4 of the 6 larvae are living; aU the larvae are stiU in their first 
instar. 
Tubes Nos. 7 and 8 were used in a demonstration at a meeting of the Entomo¬ 
logical Society of London. To No. 7 was added a small mass of yeast cells from 
a wort agar culture of S. cerevisiae and to No. 8 a small mass from a culture of B. coli. 
The eggs in No. 7 hatched within a few minutes, those in No. 8 during the following 
night. 
Beef broth. No. 14, 1 larva in first and 3 in the second instar. 
No. 16, 3 larvae in first and 2 in second instar. 
No. 17, 4 larvae in first and 1 in the second instar. 
No. 18, 1 larva has died; 4 are stUl in their first and 1 is in its second 
instar. 
Beef broth and Filtrate. No. 19, no change. 
No. 20, another egg has hatched; 3 larvae are in their first and 1 in its third 
instar. 
No. 21, no change. 
No. 23, another egg has hatched; the first larva is still in its second instar. 
No. 24, 2 more eggs have hatched; the older larva is now in its third instar. 
After the Z2>rd day. 
Distilled water. No change. 
Distilled water and Filtrate. Nos. 7 and 8, there is a marked difference in the 
growth of the larvae in these two tubes. Approximately the same bulk of B. coli 
was put into No. 8 as there was of yeast cells into No. 7. The larvae in No. 7 have 
only reached the second and third imstars while those in No. 8 are aU either in the 
third or fourth instar. This difference can hardly be owing to a minute difference 
in mass of the bacteria or yeasts which were added; probably it is due to the medium 
(distilled water with a httle filtrate of a broth culture of B. coli added) being better 
adapted for the multiplication of bacteria than the yeasts. The fourth instar larvae 
in tubes 9 and 10 and the remaining larva in tube 11 are all marking time, having 
presumably exhausted aU the nutriment without fuUy developing their fat bodies. 
In tube 12 aU the larvae, save one, died in their first or second instars; the survivor, 
still in its first instar, is only capable of feeble movement. 
Beef broth. No. 14, 1 larva is dead. 
No. 16, no noticeable change. 
No. 17, two larvae have died, the survivors are 1 in second and 1 in third 
instar. 
No. 18, no change. 
Beef broth and Filtrate. Nos. 19 and 20, no change. 
No. 21, the larva which was in its second instar is dead. 
No. 23, no change. 
No. 24, only 1 larva in its first instar is now living. 
