1935 ] 
Immature Stages of Macrocera anglica 
25 
THE BIOLOGY AND MORPHOLOGY OF THE IMMA- 
TURE STAGES OF MACROCERA ANGLICA 
EDWARDS. 
By S. Madwar, ph.d. (Cantab.) m.b., ch.b. (Edinb.) 
D.T.M. & H. (LOND.) 
Research Institute and Endemic Diseases Hospital, 
Public Health Department, Cairo, Egypt 
The early stages of this fly are unknown and they are 
here described for the first time. The remarkable shape of 
the larva, resembling more a small earth-worm than the 
larva of a fly, makes it an interesting object of study. 
The records of the British Museum show that the fly was 
found in the New Forest, Stocken Church, Crowborough 
and Welwyn. Moreover, I have seen specimens of this fly 
from Egypt in the British Museum. They were darker than 
the English type. 
I found the larvae of Macrocera under the loose bark of 
damp moist logs of oak, ash and elm in Richmond park and 
Epping forest near London. The bark was stripped gently, 
and the larvae were found living separately each under its 
own web of saliva. The web is hygroscopic and on it are 
suspended droplets of clear fluid. The web consists of fine 
threads about three to four inches long. In constructing this 
web, the larva anchors one end of its slimy salivary thread 
to the bark ; the head is then raised, and the thread is worked 
forwards and backwards. Inside the web, a stouter thread 
runs from one end to the other. 
The movements of the larva are very characteristic. It 
glides with greatest ease and even with rapidity over the 
even surface of fungoid growth covering the bark. In do- 
ing so, it is assisted by the fine threads which it emits so as 
to bridge over these inequalities. It moves forwards and 
