BY T. L. BANCROFT, M.D. 



59 



with enibryo-fllaria. To account for the propagation of the fllaria 

 of the crow was hopeless owing to the omnivorous diet of that bird ; 

 so a study of other birds was made, which led to the discovery of 

 haamatozoa in fourteen species, among which is the Blue-Mountain 

 Parrot, an exclusively honey-eater. 



This find of filaria in a parrot is fortunate for it has reduced 

 the difficulties regarding the propagation of filariae, of birds at any 

 rate, to a minimum. 



The Blue-Mountain Parrot harbours, as most birds do, a blood- 

 sucking louse. 



Helminthologists state that the life- cycle of a filaria requires 

 two hosts. 



The mosquito has been almost proved by Mans on to be an 

 intermediary host of Filaria hominis, and an Entomostracon 

 " Cyclops" has apparently been shewn to transmit the Guinea-worm. 



I believe I am justified in assuming the following : — 



1st, The lice of birds are the intermediary hosts in the life- 

 history of filarial of birds. 



2nd. Birds infect themselves by picking lice from an infected 

 bird and afterwards re-infect themselves by picking their own lice ; 

 this would account for the immense numbers of haamatozoa in some 

 birds. 



Of birds harbouring haamatozoa, one-half are found infected. 



As one would expect the older the individual and therefore 

 the longer exposed to infection, the more is it likely to contain 

 haBmatozoa. I killed a butcher-bird and its young one full feathered, 

 the old bird's blood contained filaria, whilst the young one's did 

 not. There are exceptions to this rule for occasionally very young 

 birds are found infected, whilst old ones are free from haamatozoa. 

 "With regard to the adult or parent worms, I had great difficulty 

 in finding these and have succeeded in discovering only six speci- 

 mens, viz., four mature females in butcher-birds (two in the peri- 

 toneum and two under the fascia of the muscles of the thigh), one 



