126 
ZOOLOGY: J. P. BAUMBERGER 
tritional requirements of larva and adult is probably due to the rapid 
growth in the former which requires proteins and leads to fatal changes 
in their absence. 
Owing to the habit of the larvae of constantly agitating the surface 
and carrying yeast cells throughout the medium, fermentation is greatly 
increased and the increase in alcohol resulting may serve as a protection 
to the larvae against destructive molds and putrefactive bacteria. 
The anaerobic conditions resulting may increase the percentage of the 
albumin in the yeast cells'^ and thus increase their food value. 
The number of larvae present in a culture determines the degree to 
which the yeast will be spread through the medium. If few larvae 
are present the cultures become contaminated with injurious molds and 
bacteria; if a large number of larvae is present the food remains 'sweet.' 
The depth to which the larvae work their way below the surface is 
an important factor in this connection. This depth is determined by 
the consistency of the medium, as the larvae will go as deep as a bubble 
of air will remain attached to the two projecting posterior spiracles. 
The instant this bubble is lost the larva 'backs-up' until another is 
found. It would seem therefore that a medium of a jelly-like homo- 
geneous consistency would be best, and I believe the geneticists are 
striving for this end when they mash and boil their banana. 
I Baumberger, J. P., and Glaser, R. W., Science, New York, N. S., 45, 1917, (21-22). 
2Bogdanow, E. A., Arch. Anat. Physiol, Physiol. Ahth., Leipzig, 1908, Supple., (173). 
3 Buchner, P., Arch. Protistenkunde, Jena, 26, (1-116). 
4 Glasgow, H., Biol. Bull, Woods Hole, Mass., 26, (101). 
^ Moufang, E., Wochenschr. Brau., Berlin, 30, (113-116). 
6 Nagel, C, Zs. Spirit Ind., Berlin, 35, (185). 
7Loeb, J., Science, New York, N. S., 41, 1915, (169-170). 
^ Delcourt, A., and Guyenot, E., Bull. sci. France Belgique, Paris, 45, 1912, (249-332). 
^Wildier, E., La Cellule, Louvain, 18, (314-332). 
10 Harden, A., and Young, W. J., London, Proc. R. Soc. 78B, (369-375). 
II Guyenot, E., Paris, C. R., soc. biol., 45, pt. 1, 1913, (178). 
12 5alomon, Miinchener med. Wochenschr., 63, 1916, (445). 
13 Schultze, P., Zool. Am., Leipzig, 39, (199-202). 
i^Henneberg, W., D. Essigind., Berlin, 6, 1902, (333). 
i^Loeb, J., /. Biol. Chem., Baltimore, 23, (2-5). 
1^ After sending this paper to press, I learned that Loeb and Northrop, /. Biol. Chem., 
Baltimore, 21 y 1916, (309-312), had already published a confirmation of Guyenot's 
conclusion. 
" Schoenfeld, F., and Hirt, W., Wochenschr. Brau., Berlin, 29, (157-159, (174-178)). 
