ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 



311 



flows to the side next to the Microscope, and is prevented by a raised 

 ledge from running off, except through the two tubes on either side 

 of the Microscope which are connected with the waste-pipe. Twelve 

 nails in the sides and on the top of the upper plate are for the cords 

 used in tying the animal. 



The author also describes and Fig. 54. 



figures the arrangement of water- 

 bath, heating and irrigating appa- 

 ratus, cork plates, &c., of which he 

 made use, and gives directions for 

 examining the mesentery, as well as 

 a full description of the results of 

 his researches. 



Watson's CoUectors' Pocket 

 Microscope. — This instrument (fig. 

 54), made by Messrs. Watson and 

 Sons, is a small compound Micro- 

 scope with 4 in. body-tube and 

 a 2 in. objective, mounted on an 

 upright pillar, which screws into a 

 round brass base-plate. There arc 

 universal motions, so that the tube 

 may be pointed in any direction for 

 the best illumination of the object. 

 The body-tube slides in an outer 

 tube or jacket for adjustment of 

 focus, and at the object end of this 

 is a hollow cut for a test-tube to lie 

 across the optic axis, being held 

 there while being examined by an 

 elastic band. Ordinary slides (3 

 X 1 in.) may also be held in the same manner. The instrument, and 

 three glass specimen tubes, pack into a flat case 5^ x 5| x 1^ in. 



Cheap Dissecting Microscope.* — Prof. C. E. Barnes writes as 

 follows : — " No laboratory or workers need be unsupplied with dis- 

 secting Microscopes. If even the cheapest form manufactured by the 

 opticians is beyond the means of the school or individual, an effective 

 stand may be made as follows : — Into any block of wood of suitable 

 size fix upright a short piece of stiff wire or rod having a smooth 

 surface. Bore a hole in a fine-grained cork, a little to one side of 

 the centre, so that the cork will slide smoothly on the rod. Bend 

 one end of the smaller wire into suitable shape to hold whatever lens 

 is at hand, and make a hole of proper size in the cork at right angles 

 to the first. This arrangement gives ample and smooth movements 

 of the lens in any direction for adjustment. The plan may be 

 elaborated to any desired extent. If the rod be fixed in a plain 

 piece of board, dissecting may be done on a piece of glass laid flat on 



Bot. Gazette, x. (1885) pp. 427-8. 



