2000 



Journal of Applied Microscopy 



not inferior to those made with far more elaborate and expensive apparatus. 

 The advantages claimed for the apparatus may be summed up as follows : 

 Weighs only three and one-half pounds. The microscope in ordinary use at any 

 position or adjustment does not have to be moved or in any way disturbed when 

 making a photograph. The camera is brought into alignment with axis of micro- 

 scope by a single movement as a whole and without refocusing, or even looking 

 at the image on the ground glass, the same definition and amplification as seen 

 in the microscope can be obtained. The author states that it takes him from 

 twenty to thirty seconds to attach the camera and adjust ready for an exposure. 

 Is very inexpensive. c. w. j. 



SOME OBSERVATIONS ON THE SEVENTEEN YEAR 



LOCUST. 



The cicada photographed had been feeding lower down upon the same trunk, 

 and was disturbed by the motions made in adjusting and focusing the camera 

 so that it moved away from its then location and, after a time, readjusted itself 

 in the one where it was photographed. When moving, the beak is folded back 

 between the fore legs at an angle of about 45 degrees, so that the tip is just free 

 from the surface of the bark. As it begins to feed, the tip of the beak is brought 



Fig. 1. — Male locust feeding on the bark of a young peach tree. 



forward so as to become more nearly perpendicular, and is rested against the 

 bark. The insect then " backs up " so as to bring the upper end of the beak in 

 perpendicular position above the tip, which is already resting against the bark. 

 This backward movement on the part of the insect is accompanied by a setting of 

 the legs in a firm position, and is accomplished by an actual pulling back of the 

 body by the hind legs rather than a mere settling closer to the bark (Fig. 1 ). With 

 the beak now in perpendicular position (see Fig. 1), the setae apparently are pro- 

 truded through the tube which the beak forms (see Fig. 2) and this is accompanied 

 by a slight sinking of the head as the beak itself appears to be forced to a slight 



