INVERTEBBATA, CRYPTOGAMIA, MICROSCOPY, ETC. 



505 



Fig. 29. 



Improvements in Cell-cutting.* — Cells cut from thin slieet wax 

 or lead are rapidly coming into use in America. They can be built 

 up one upon another to form deeper cells, but are most applicable where 

 great thickness is not required, and have the great advantage that they 

 can be prepared, as wanted, by anybody, of any required size, with very 

 little trouble, and almost without expense. The elegant preparations 

 of Mr. Merriman at the Buffiilo meeting of the American Society of 

 Microscopists were mounted in cells of wax cut by Streeter's punches. 



These instruments, as subsequently improved 

 and as now made, are represented in section by 

 Fig. 29. There is a set of four concentric tubes of 

 iron or hard brass, of equal length, fitting smoothly 

 within each other, and turned to a cutting edge at the 

 lower end. When using the punches, the cutting 

 edges are to bo moistened with water to prevent 

 sticking to the wax, and the wax laid on some 

 book-leaves or writing-paper to form a firm, smooth 

 cushion. The smallest punch is then puslied through the wax sheet 

 with a slightly rotating motion, and then the next one is placed over it 

 and pushed down in the same manner, and so on, to the largest. The 



U mi 



Fig. 31. 



Fig. 32. 



Fig. 30. 



':«u;:^J 



inner punch is next witlidrawn by a wooden peg or pencil thrust into 

 it, and the others drawn out one after the other by tho little finger. 

 Each ring of wax is then pushed out of its punch with tho top of 



Am. Nat.,' xiv. (1880) p. 05. 



VOL. III. 



'J. L 



