1900] MICROSCOPICAL JOURNAL. 265 



useful and substantial support, which overcomes these dif- 

 ficulties, and enables the photographer to successfully 

 operate with his apparatus at an angle of 45° to the ver- 

 tical. The arrangement is a good one, and is already in 

 use in medical circles. 



Make Notes. — One important habit which the micro- 

 scopist should .cultivate is that of making copious notes 

 of observation!. He should never be without his memo- 

 randum or note book. No more profitless work can be im- 

 agined than collecting natural history specimens and ma- 

 terial without some specific aim or object. Every obser- 

 vation made should be carefully recorded, and the date of 

 capture, locality, and, where possible, the food-plant, 

 should always be attached to the specimens when these 

 are mounted. For field memoranda the use of a stylogra- 

 phic pen is advisable, as pencil writing is apt to rub and 

 efface in time by the motions of the body. A larger re- 

 cord book for more extended notes should be kept at home 

 for biological details. When studying insects, for instance, 

 notes on adolescent states, which it is intended to rear to 

 the imago, cannot be too carefully made, or in too much 

 detail. The relative size, details of ornamentation and 

 structure, dates of transformation from one state to an- 

 other — indeed everything that pertains to the biography 

 of the species — should be noted down, for where exact data 

 are so essential, little or nothing should be trusted to mere 

 memory. 



Wood Sections. — In photographing wood sections with- 

 out a lens, Herr Fomra places a piece of tinfoil on one 

 side of the section and the film surface of a piece of bro- 

 mide paper against the other side. A good impression — 

 showing clearly the rings and rays of the wood — is pro- 

 duced in about a half a minute when a metallic point neg- 

 atively charged by an influence machine is brought with- 

 in two inches of the paper. It is explained that the paper 

 becomes negatively charged, and a photographically ac- 



