60 



THOMAS L. BANCROFT. 



Metamorphosis of Fitoria nocturna in Mosquito's thorax, x 200 diameters. 



Fig. 1 Normal appearance of filaria in the blood. 



Figs. 3, 4, 5, 6, Stages of the metamorphosis, 1 — 5 — 10 — 16 

 respectively. A = Head; B = Tail. 



