684 8UMMARY OF CURRENT RESEARCHES RELATING TO 
moderate price. It is adapted for cutting objects imbedded in celloidin 
or in paraffin, or by the ether-freezing method. It is constructed of 
iron, the greater part of the surface being nickelled and the rest var- 
nished. It is clamped to the table by a large binding-screw d, and if 
required to cut under water or alcohol, it is fixed to a board placed 
vertically. 
The microtome proper is of the Ranvier type. The micrometer- 
screw is moved automatically by an excentric which is capable of adapt- 
ing itself to one or more divisions of a graduated circle b. The requisite 
number of divisions is determined by the operator, each corresponding 
to a micron when the handle k is pushed forward. The excentric is 
set by merely turning a ring, and thus gearing the microtome for 
1 to 36 microns. 
The knife-carrier is attached to the vertical piece a, and moves on 
the pivots s s when the handle k is pushed backwards or forwards. 
The illustration (fig. 119) shows the apparatus as arranged for ether- 
freezing. 
(4) Staining- and Injecting:. 
Weigert Methods of Staining.* — Prof. C. J. Herrick reports a 
series of experiments with the Weigert staining methods in studying 
the components of the cranial nerves in bony fishes, which rests largely 
on the myelination of the nerves. The results are given for the dif- 
ferent fixing reagents, mordants, &c., and form a body of valuable 
suggestions for those who propose applying these methods to the lower 
Vertebrates. 
Fixing and Staining Starch-grains. f — The results described on 
p. 639 were obtained by Herr J. H. Salter by the use of the following 
processes of fixing and staining. 
Flemming’s mixture was found, on the whole, to bo the best fixing 
material. Sublimate-alcohol and picrin-alcohol also gave good results 
when the staining reagent used was acid-fuchsin. 
For staining the plastid in which the starch-grains are imbedded, 
acid-fuchsin and iron-haematoxylin gave much the best results, especially 
when the fixing material used was sublimate ; 20 grm. of acid-fuchsin 
were used in 100 ccm. of anilin- water. The starch-grains themselves 
may be stained by methyl-violet or gentian- violet in aqueous solution, 
both showing the stratification fairly well, especially if the section be 
first treated with a concentrated aqueous solution of orange G. For a 
double stain the material may be fixed by sublimate and stained by acid- 
fuchsin followed by methyl- or gentian-violet, the excess of violet being 
then removed by orange. The chloroplasts and leucoplasts, as well as 
the whole of the cytoplasm, take up the fuchsin, while the starch-grains 
absorb the violet. 
Sudan iii., a Selective Stain for Fat.t — Dr. A. G. Nicholls confirms 
the observation of Rieder, who found that Sudan iii. is useful for histo- 
logical work, especially for differentiating fat. A saturated solution of 
Sudan iii. in 96 per cent, alcohol is, after filtration, diluted two-thirds 
* N. York State Hospital’s Bull., Oct. 1897. See Amer. Nat., xxxii. (1898) 
p. 802. t Jahrb. f. wiss. But. (Pfeffer u. Strasburger), xxxii. (1898) pp. 118-21. 
f Microscopical Bulletin, xv. (1898) p. 31. 
