72 ENTOMOLOGICAL SOCIETY 



it was thus obviously impossible for him to properly care for so 

 large a collection, covering different orders. Mr. Ashmead also 

 made a statement of the condition of the collection in other orders 

 than Lepidoptera, mentioning in particular the Coleoptera and 

 Hymenoptera, and referring to the enormous number of types in 

 the latter greatly in excess of those in the Lepidoptera. 



The concluding paper was by Mr. C. B. Simpson, and was 

 entitled : 



THE ALIMENTARY CANAL OF CERTAIN LEPIDOPTEROUS 



LARVAE. 



By C. B. SIMPSON. 

 (Author's Abstracf.} 



The forms used were the larvae of Carpocapsa pomonella, 

 Clisiocampa americana, and Pieris rapce. The alimentary 

 canal is divided both anatomically and embryologically into three 

 regions : the fore-intestine, the mid-intestine, and the hind-intes 

 tine. The embryology and general anatomy of these different 

 parts were given, illustrated by sketches. 



The fore-intestine extends from the mouth to the mid-intestine, 

 and is composed of the following parts: the mouth cavity, the 

 pharynx, oesophagus, and the oasophageal valve. 



Descriptions of these different parts were presented and special 

 attention was given to the embryology and structure of the ceso- 

 phageal valve which was illustrated by sections. The walls of 

 the fore-intestine consist of an external layer of circular muscles, 

 an internal longitudinal layer, a basement membrane, and a layer 

 of epithelial cells, forming a syncitium, the inner portion of which 

 was strongly chitinized, thus forming a chitinous intima. 



The mid-intestine is about half of the length of the canal in full 

 grown larvae and is the true absorbing organ. The histological 

 elements are : an external layer of longitudinal muscles ; an inter 

 nal circular layer, a basement membrane, a single layer of epithe 

 lial cells, and the peritropic membrane. The cells of the epithe 

 lial layer are of two kinds, the ordinary epithelial cells and the 

 mucous cells. The structure of these cells was given and sections 

 shown. The peritropic membrane, that membrane immediately 

 enclosing the food, is believed by the author to be the coagulated 

 secretion of the mucous cells. 



. The hind-intestine has essentially the same structure as the fore- 

 intestine, except that the muscular and chitinous layers are much 

 stronger, especially the circular. The accessory organs present 

 are the Malpighian tubules and the rectal glands. 



The functions of these parts were given with special attention 

 to digestion. 



