SIXTH WEEK. 



NEEDED. Dissecting apparatus as for the fourth week. A num- 

 ber of butterflies or moths and caterpillars. 



FIRST HOUR. Carefully study and describe the mouth parts. 

 Draw the venation of both front and hind wings of one or more species. 

 Indicate the homology between the veins in the wings of these insects 

 and those of grasshoppers. For the peculiar terms used in this order, 

 compare the introduction of Morris' Synopsis of I^epidoptera . 



SECOND HOUR. Denude the thorax of its scales, study and draw, 

 naming the parts exposed. (The scales are much more readily re- 

 moved from moths than from butterflies.) 



THIRD HOUR. Describe the peculiarities of external structure of 

 a caterpillar. If the caterpillar is hairy, remove the hairs with the 

 scissors. Lay open the body as directed in the fourth week, and com- 

 pare the internal structures with those of the grasshopper. 



