60 JOURNAL OF ENTOMOLOGY AND ZOOLOGY 
been tried with little effect. A number of parasites are named 
and described in this bulletin. The most satisfactory way to 
hold these in check is by the ordinary lime-sulphur spray some- 
what diluted. C. A. Perrin. 
THE STRUCTURE AND METAMORPHOSIS OF THE 
FORE-GUT OF CORYDALIS CORNUTUS L. 
ROBERT MATHEWSON 
Jour. of Morph., Vol. 23, No. 4, 1912. 
The fore-gut has five well marked regions: pharynx, esoph- 
agus, gizzard, portion between esophagus and esophageal valve, 
and esophageal valve. 
The pharynx is provided with a series of dilator muscles 
attached to the walls of the head. The esophagus has a large 
number of longitudinal folds. The gizzard has powerful teeth, 
which from their arrangement and the arrangement of the 
muscles in this region, seem to show that they are for grinding 
and crushing. The esophageal valve is short and is lined with 
four strongly chitinized ridges which alternate with the ceca. 
The metamorphosis of the fore-gut is of a generalized type. 
The larval epithelium becomes partly broken down and the 
cells destroyed are replaced by the division of rejuvenated larval 
cells. The nuclei always divide mitotically and every spindle is 
located at the side of a vacuole. The dividing cell migrates 
towards the inner surface, though it retains connection with the 
basement membrane. The histolysis and histogenesis of the 
muscular coats are also generalized processes. The muscles 
liquefy in place. The greater number of the larval nuclei be- 
come rejuvenated and around them as centers the new fibrillar 
structures are developed. 
The role of the leucocytes is a comparatively unimportant 
one. They are present throughout pupal life and seem to 
engulf small particles of the broken down tissues. They do not 
take active part in the destruction of the larval muscles or 
epithelium. 
The paper is illustrated by four plates from very fine photo- 
graphs. 
