C. Strickland 
223 
diverticulum, which is at first tubular, but later ends in a large bilobed 
sac, sometimes, though incorrectly, referred to as the ‘ crop.’ The 
midgut is dilated slightly, and is succeeded by the small intestine, which 
terminates at the point of entry of the Malpighian tubules. The hindgut 
commences at this point, and ends in a dilated portion termed the 
rectum, which opens to the exterior at the anus. 
In this paper the term ‘ crop ’ will be retained only for the sake of 
brevity. 
Fig. 1. Showing the anatomy of the alimentary tract of Lucilia. 
The methods of examination of the fut contents. 
The parasites were studied both in the living state and in stained 
preparations. Living specimens were obtained by dissecting out the 
flies’ intestinal tract in saline solution, removing portions of it to a 
slide, and protecting with a cover-glass. Stained preparations wei’e 
made from isolated portions of the gut, opened up in a small drop of 
salt solution and smeared out in the usual way. They were fixed in 
absolute alcohol, and finally stained with Giemsa diluted 1 : 20. It was 
found that a weak solution of the stain gave less diffuse staining than 
a stronger one. 
Morphology. 
The general character of the parasite varies in the different regions 
of the intestine in which it is encountered. The description of the 
various forms may therefore be conveiriently arranged according as they 
are found (i) in the oesophageal diverticulum or ‘crop,’ (ii) the midgut, 
\ 
Parasitology iv 15 
