THE FLY. 91 



and it may not be, therefore, strictly correct. But if I can fairly 

 describe what I have seen, my readers, I think, will be of opinion 

 that there is good ground for the suggestion. At the end of the 

 tongue is a tube which passes into the thorax, where it is at once 

 connected with a button-like process at the commencement of the 

 chyle-stomach. This tube then runs along away through the 

 thorax into the abdomen, where it swells out into a pouch of two 

 lobes. Here the food is in the first instance received, and stored 

 up as it is similarly stored in the paunch of the ox, sheep, and 

 goat. When full it is distended to an enormous size. From this, 

 at its leisure, our Httle fly sucks up its nutriment ; perhaps into its 

 mouth. Whether so or not, the food certainly passes into the 

 button-like process — called a proventriculus — which is divided into 

 compartments, and so through the chyle-stomach into the intestine. 

 This is convoluted in the abdomen, and when drawn out is about 

 three times the length of the fly itself. Towards the end is a 

 singular and beautiful process, called by Mr. Lowne, in his work 

 on the Blow-fly, the "Rectal Valve"; but I think it is not cor- 

 rectly figured there. I have dissected it out, and found it to be 

 reticulated, or net-like (see Plate XXVI.) ; then after contracting 

 very much it enters a cup-like part, which is again contracted so 

 as to take the form of a funnel. After this the intestine swells 

 into a large sac, or bag, having four curious processes, called 

 by Mr. Lowne " Rectal Papillae." From being supplied with 

 comparatively large air vessels, they are evidently important in 

 the economy of the fly, but for what purpose is not clearly known. 



The next thing to notice in connection with the alimentary 

 canal, or nutritive organs, are the salivary glands. These, like the 

 other organs described, commence in the head. In the thorax 

 they take, in the House-fly, and also in the Blow-fly, a convolu- 

 ted form on either side of the chyle-stomach. On entering the 

 abdomen they are straight, and the two pass on to the end. 



There is still another adjunct to mention, namely, the long 

 bead-like processes attached to the lower part of the alimentary 

 canal, and supposed to be biUary ducts. It will thus be seen that 

 this organ is most highly developed. 



The reproductive organs again are a study of themselves ; 

 but it will make this paper too long to attempt their description. 



