110 Herpetomonas and Critliidia 
consequence, my drawings show the same nuclear structure as 
Minchiu’s. 
At times I have had some difficulty in obtaining well stained 
preparations with Giemsa’s solution, the flagellum, especially, staining 
badly. In such cases I have found that good results may be obtained 
by immersing the preparations for some hours in serum (ordinary 
horse-serum preserved with a little chloroform); afterwards they are 
rinsed in water and stained in the ordinary way\ 
II. Grithidia calliphorae n. sp. 
This species was only found once and so I cannot give a description 
of the whole life-history. It is certainly different from the Herpeto- 
vionas also found in the gut of Galliphora eri/tlirocephala, but it is 
possible that this species is identical with G. muscae-domesticae (Werner), 
as described by Rosenbusch (1909). 
The full-grown organism is 12-21 fx long (without the flagellum) 
and 2 p, broad; the whole flagellum is 19-31/u. long, the extracellular 
part of it measures 15-28 ya. It looks rather like a Herpetomonas 
Diagram I. Grithidia calliphorae. 
1. Herpetomonas-form. 2. Crithidia-form. 
3-8. Trypanosome-forms. 
9. Herpetomonas-form (wet fixation, iron-liaematoxylin). 
Nearly all the samples of Giemsa solution sent to me by Messrs Griibler and Holborn 
of Leipzig have given excellent results, and I desue to thank the Firm for the amiable 
way in which they helped me in the matter of stains. 
