1889.] 



MICE0SC0P1CAL JOURNAL. 



.83 



animal. These forms were not found among the floating mats of Os- 

 cillaria on the surface, but were at the bottom of several feet of water 

 among the Pleurosigma and other diatoms and in detached filaments. 



NOTES ON APPARATUS. 



The King Microtome. — This microtome, by J. D. King, Edgar- 

 town, Mass., will cut anything that can be cut with any microtome, and 

 do its work as well as the best, but it is designed especially for botan- 

 ical work, or for cutting any hard substance that requires the greatest 

 possible rigidity in the instrument. 



The knife is attached to a heavy nickel-plated iron carriage, A, by a 

 steel clamp and shoe, b and c, with milled head-screws, a. The car- 

 riage runs on a solid iron track, h and B^ which is held to a table by a 

 clamp-screw, k. 



For cutting very hard objects, like the wiry stems of plants, or the 

 chitinous skeletons of insects, there is an attachment with a very stout 

 blade, on the principle of a carpenter's plane, d, which screws on to the 

 carriage in place of the knife, and like the knife it can be used straight 

 aci'oss or obliquely. 



Diameter of well,_/, £ of an inch ; depth of well, i^ inches ; depth 

 of well with chuck, L % i inch. 



For cutting soft material, paraffine may be cast directly into the well, 

 or into a chuck, not shown, which is held firmly by being screwed into 

 the bottom of the well. The adjustable chuck, X, is intended for harder 

 material. 



Microtome No. i gauges to 1-10,000 of an inch by turning the ratchet, 



(Cut about one-third actual size.) 



