THE CANADIAN ENTOMOLOGIST 43 



again. Here, however, was an excellent and unusual opportunity 

 to secure a photograph of a wolf spider. For the living, unin- 

 jured Lycosid is so nimble and nervous that it is a most difficult 

 matter to photograph it successfully, while it is very hard to "set 

 up" the dead spider properly. So I carefully carried my spider 

 home. 



Here a few concise, technical notes may be of interest to the 

 photomicrographer. The negative of the accompan^'ing photo- 

 graph was made with an ordinary whole plate view-camera pro- 

 vided with both front and back focussing. A half plate or even 

 quarter plate camera would have served equally well or better, 

 but no smaller instrument of sufficient extension was available. 

 The lens used was an Aldis photomicrographic anastigmal of 2 in. 

 focus, an admirable little lens of moderate price that can easily 

 hold its own with much more expensive objecti^'es. My camera 

 and object stand is a home adaptation of the swinging frame of 

 the photo-engraver. It consists of a board 4 ft. long by 14 ins. 

 wide swung by cotton ropes at the four corners from two light 

 trestles about 3 ft. high, and is a device I find very useful to avoid 

 vibrations during long exposures. 



At one end of the board is a narrow, longitudinal slot, one foot 

 long, through which a bolt with a wing nut fastens the camera 

 firmly at any position along the slot. As the object must be 

 placed very close to a lens of such Short focus, if the latter is mounted 

 in a lens board in the ordinary way, the shadow cast by the rela- 

 tively large camera front is sure to cause trouble. To obviate 

 this I have the lens mounted at the truncated apex of a copper 

 cone, 3 ins. long, the base of which, 23/^ ins. in diameter, screws 

 into a lens flange attached to the usual lens board which fits the 

 camera front. A stand was made for the spider with several small 

 blocks of wood, about 8 in. x 3 in. x 1 in. thick, piled up like steps 

 of stairs. On these, by means of dark-room pins, was fastened a 

 curved piece of smooth, white paper, with its top sloping away from 

 the lens. The middle of the curve formed a little shelf just op- 

 posite the lens, and on this the spider was placed. This arrange- 

 ment offered a plain background, and a shadowless support on 

 which the spider was carefully posed, her limbs and palps being 

 put in position with a couple of botanical needles. 



