STUDIES ON AVIAN H^MOPROTOZOA. 645 



negative side also can be relied upon, for reasons "which are 

 given below ; in this respect they differ from most previous 

 tables and estimates of trypanosome-infections of birds. The 

 figures suffice to show that, so far as occurrence is concerned, 

 the bii-ds with which I have worked do not bear out the dismal 

 statistics given by many of the researchers (e.g. Ziemann, 

 the Sergents, Button and Todd, etc.) 



Intra-cellular Parasites in the Chaffinch. — In 

 several of the chaffinches I noticed, when looking for trypano- 

 somes, the presence of Halteridia; except in one case, which 

 I shall describe shortly, these were only scanty in number. 

 I have also observed, in three cases, an interesting leucocytic 

 parasite, which is quite different in appearance from the 

 celebrated Le ucocytozoon ziemanni of owls. 



What is undoubtedly a similar parasite has been observed 

 independently by Dr. Stevenson, of University College, in 

 smears of the blood of a greenfinch, which he has kindly 

 shown me for comparison. 



2. Methods op Work ; Attempts at Transmission by 

 Mosquitoes ; Technique. 



Fresh blood was always taken, in the living bird, from a 

 fairly large marginal vein of the wing-, prominent where it 

 ci'osses the arm on the inner side, immediately below the 

 elbow-joint. A fine-pointed surgical needle of the triangular- 

 bladed kind was used. It is essential that the point be 

 sharp. Unless a clean prick is obtained, the blood does not 

 exclude freely in a good drop, but suffuses beneath the skin, 

 raising a swelling from which blood cannot be got satisfac- 

 torily. As a rule bleeding stops quickly. Should it give any 

 trouble, a swab of cotton-wool, dipped in lysol, is applied to 

 the wound and the wing closed up over it and held to the 

 side of the body for a few minutes. The vein soon recovers 

 from this little operation, and can be used again, if desired, in 

 a couple of days or so. 



Culture-tubes. — The use of culture-tubes has been of the 



