REVISION OP ELEOmiNT BLAISDEI.L. 7 



SO that they approximate their fresh condition. The specimen, when 

 ready, is grasped between the thumb and index finger of the left 

 hand, dorsum to the palm, then with a lance-pointed dissecting 

 needle depress the last two ventral segments, pass the needle internal 

 to the sternite of the seventh segment and forward along the inner 

 surface of the sixth and fifth abdominal segments, cutting first to the 

 right, then to the left, detaching the integumentary attachment along 

 the pleural region ; when this is done, with a curved or hooked pointed 

 needle pull out the viscera. Place them on the stage of a dissecting 

 microscope and carefully remove the ensheathing sclerites and mem- 

 branes from the genital organs; the latter should now be washed in 

 60 per cent alcohol, then placed into another bath of 60 per cent 

 alcohol to wdiich a little glycerine has been added to prevent too 

 rapid drying while being studied. Remove and wipe with a camel's 

 hair brush, and mount on a white bristol-board slide for the micro- 

 scope, a minute drop of glue being used for the purpose. 



Study the dorsal surface first and be sure to orient the specimen 

 so that the surface is parallel to the focal plane; when finished wet 

 slightly and remove from the slide, wash in water to remove the glue, 

 throw into the alcohol and glycerine, remove and wipe and mount as 

 before, but in a reversed position, and study the ventro-lateral sur- 

 faces. When this is done remove as before, Avash in alcohol, and 

 mount on a small piece of cardboard and place on the pin beneath 

 the insect for future study. 



Parts to observe about the female organs: 



Dorsal surface. — (xeneral form, pubescence, relation of the valves 

 to each other, apices, cercopoda, dorsal i)lates, and superior pudendal 

 membrane. 



Yeiitrolate^^al surfaces. — General surface contour, pubescence, basal 

 prominences, submarginal grooves, position of the fossse and cer- 

 copoda, genital fissure, and inferior pudendal membrane. 



Parts to observe about the male organs : 



Dorsal surface. — General surface contour and form of the edeago- 

 phore and its basale and apicale, presence or absence of a membranous 

 area or groove. 



Ventral surface. — General form and condition of the membrane, 

 alse; clavse, form and relation to the edeagus; degree of inflexion of 

 the sides of the basale. In the male the sternite of the seventh seg- 

 ment must be removed separately and studied in conjunction with 

 the edeagophore. It is of value in classification. Prepare and 

 mount as the other organs. 



In order to study the relation of the sclerites of the retractile seg- 

 ments and rejoroductive organs, clear with liquor potassi. 



The study of the tarsi should be most carefully done. I have used 

 a bull's-eye condenser for concentrating the light, and while holding 



