116 SUMMARY OF CURRENT RESEARCHES RELATING TO 



New Method of making Celloidin Serial Sections.* — F. Maier cuts 

 celloidin sections under 75 p.c. alcohol and transfers them to slides ; 

 there should be a margin of celloidin outside the tissue of from 0*25 to 

 • 5 cm. The sections are pressed firmly down on the slide with blotting 

 paper. Over the series is poured a mixture of oil of cloves 1 part, and 

 absolute alcohol 9 parts ; this is allowed to remain until the celloidin is 

 soft, i.e. from 15 to 30 seconds ; the superfluous fluid is poured off, and 

 then the slide is laid flat for a while in order to let the sections get fixed. 

 Then a mixture of ether and alcohol is poured over the series in order to 

 remove all traces of oil of cloves ; this is removed by evaporation merely. 

 After 15 to 30 seconds sulphide of carbon is poured over the series and 

 allowed to act for 10 to 15 minutes. All traces of the carbon sulphide 

 are removed by means of 96 p.c. alcohol changed more than once. After 

 this, down-graded alcohols to water, in order that staining, etc., may be 

 carried out in the usual way. 



The object of this technique is to make sections of any thickness 

 stick to the slide. 



Utilizing Organized Structures as Directing Marks for Plastic 

 Reconstruction. | — J. T. Wilson described over ten years ago J a system 

 for obtaining directing marks in microscopical sections for the purposes 

 of plastic reconstruction. In his new system he still builds up an em- 

 bedding chamber on a base-plate, but has discarded the Naples bars, and 

 has adopted an apparatus the dimensions of the component parts of which 

 may be varied as desired. 



The base of the embedding chamber is formed by a brass plate a 

 (figs. 21 and 22), through which are bored two pairs of cylindrical holes b, 

 each about 3 mm. in diameter. The ends of the embedding chamber 

 are formed by rectangular brass plates c, set up upon the base-plate ; 

 they are held in position by projecting dowel pins d, which fit into the 

 holes in the base-plate. The lower end of each end-plate is provided 

 with two socket holes e. These fit over two pins /, which project 2 to 

 3 mm. up from the base-plate. The calibre of the pins is 1 mm. or less, 

 and the distance between them must be exactly the same at either end, 

 2 to 3 mm. 



In order to carry out the nerve-strand method of embedding, a fila- 

 ment is gently stretched around the two pairs of pins, and the filament 

 must be taut but not strained. The loose ends should be crossed on the 

 plate at one end and held there in position, while the corresponding end- 

 plate is placed in position and its dowel pins firmly pressed home ; the 

 nerve -filament is thus securely clamped. The second end-plate is simi- 

 larly treated. This done it will be found that the two parallel nerve- 

 filaments are in contact with the surface of the base-plate. Two pieces 

 of wire (common pins decapitated) are inserted between the surface of 

 the base-plate and the nerve-strands, close to the end-plates. The em- 

 bedding chamber is then completed by the addition of the special side- 



* Miinchen. med. Wochenschr., lvii. (1910) pp. 637-8, through Zeitschr. wiss. 

 Mikrosk., xxvii. (1910) pp. 385-7. 



t Zeitschr. wiss. Mikrosk., xxvii. (1910) pp. 227-32 (2 figs.). 

 j See this Journal, 1900, p. 735. 



