1898.] MICROSCOPICAL JOURNAL. 207 



to make sections of valuable museum specimens ot recent 

 and fossil woods. Mr. Robertson has found that by di- 

 rectly photographing- the surface by means of a micro- 

 photographic apparatus, excellent pictures, giving all 

 necessary histological details of the tissues can readily be 

 obtained. The recent wood surfaces are planed with a 

 steel plane, and if at all rough the surface is wet. 

 Very careful focussing is necessary, so as to get equal il- 

 lumination. An opaque focussing plate should be used for 

 rough adjustment, but the final focussing must be done 

 with a clear glass plate. The illumination was by means 

 of a magnesium ribbon fed through a fixed tube and 

 placed at an angle of 45 degrees and a distance of ten or 

 twelve inches from the surface to be photographed. An ex- 

 posure of about forty seconds with Ilford plates gave the 

 best results. — Science Gossip. 



Quick Method of Preparing Sections. — It isoften desir- 

 able to prepare sections of soft tissues in a very short 

 time. To those who are familliar with the collodion 

 method the following suggestions by Mr. M. P, Thomas 

 in the "Journal of Appeal Microscopy" will be helpful. 

 Place the tissue at night in forty per cent alcohol in the 

 dehydrating apparatus. Remove it at 7.30 the next morn- 

 ing. Leave until 10 o'clock in two per cent collodion. 

 Then place in five per cent collodion until 11.45. Arrange 

 on the cork and place in eighty per cent alcohol. The 

 material will be ready to section at 1.30. A total of 

 eighteen to nineteen hours covers the whole operation. 



Nematodes for Microtome Sections. — The following 

 methods of preparing nematodes for sectioning with the 

 microtome has been used by Dr. Kaiser with much suc- 

 cess. The main difficulty to be overcome is the curling 

 up while being killed. To prevent this place the worm on 

 a slide with a few drops of water. Over it place another 

 slide and move it slowly to and fro. This movement 

 causes the worm to straighten. As soon as the nematode 

 assumes the desired position the fixing liquid is pipetted 

 between the slides, the motion of the upper slide being 

 continued until the worm is dead. Bv this method one can 



