526 Prof. Bronté Gatenby’s Description of Dipterous Larva. 
have failed to breed out the imago so far, but hope to have 
another try. The specimen sent shows the organ—a 
fusion, I think, of a pair—extruded, but much contracted 
in the spirit. In life it was quite transparent with branched 
silvery lines running out tothe tips of the fingers or lobes. 
These I believe to be tracheae. I will send more larvae 
when I can get them. 
Aug. 11, 1918.—I am sorry that I overlooked those 
Syrphid larvae. I will place “baits” of pieces of cut 
banana stem in putrid water for them, and, if I get any 
started, I shall try to leave them with Dr. Connal to 
complete the life-history if they do not pupate before I go. 
I thought that the white “line,” running out into each 
lobe of the curious organ, was a trachea or branch of one, 
as I think I mentioned at the time. The organ shrinks in 
spirit, but in life it was a very pretty structure, the lobes 
being quite translucent with the silvery white line running 
out to the end of each. The whole organ can be withdrawn 
out of sight inside the body of the larva. I think I will 
manage to fix that little problem up all right. 
Note (October 1921).—Prof. EK. B. Poulton, whom I have 
to thank both for the opportunity of examining this 
material, and for encouraging interest during the work, 
has drawn my attention to Mr. Farquharson’s reference to 
“silvery lines” running down the tubes. These lines I 
think must be the muscles marked M in fig. VI, and not 
tracheae, as one might naturally expect.—J. B. G. 
Pirate XVIII. 
[For Explanation of Figs. V1 see accompanying teat. ] 
