ZOOLOaY AND BOTANY, MICROSCOPY, ETC. 921 



of some quickly evaporating substance on the slide — chloroform is 

 best for most purposes. The scales will form a kind of whirlpool, 

 nearly all the scales finally settling down, as the liquid evaporates, in 

 one place on the slide. Eapping the slide gently sometimes aids in 

 the collecting together of the scales, and the tip of the scalpel used 

 to scrape the scales from the insect can be washed in the drop of 

 chloroform, thus saving every scale when they are from a rare speci- 

 men from which it is desired to remove only a few scales. By 

 inclining the slide gently the mass of floating scales can be made to 

 settle on the exact centre of the glass. One part of Canada balsam 

 added to several hundred parts of chloroform, will cause the scales to 

 stick firmly to the slide. 



Mounting Hydrozoa, Polyzoa, &c., with extended Tentacles.* — 

 Mr. A. D. Michael prefers to use spirit for killing the animals. 

 Osmic acid stains too much. They should be got in good condition, 

 placed in a watch-glass, and syringed freely, and then placed under 

 a low power and watched until the tentacles are well extended. Then 

 with a fine pipette run a small drop of spirit down the side of the 

 glass, not on the polype. The creature will probably withdraw its 

 tentacles. If so, leave it alone until they expand again ; without dis- 

 turbing it run another drop down the glass. After doing this once or 

 twice the animal gets dull and heavy, drunk in fact, and then spirit 

 may be added freely, and the polype mounted. 



As a medium for mounting, spirit and water gives very good 

 results, possibly the best on the whole, but Goadby's solution preserves 

 the creatures in more natural form and keeps the sarcode harder, 

 presenting a more life-like appearance, but it is open to the objection 

 that it contains corrosive sublimate which produces a certain amount 

 of discoloration of the creature after a time. Another objection is 

 that it has a tendency to cast a sediment. For that reason it should 

 be used weaker than the book strength, adding about three times the 

 quantity of distilled water. 



Mounting Leaves of Pinus.f — Mr. H. J. Slack writes that 

 " Amongst the objects which yield beautiful results with [nitric] acid 

 and chlorate of potash treatment, are the needle-shaped leaves of the 

 pine-trees. Pinus austriaca, common in shrubberies, is a good one 

 for the purpose. Quite clean leaves should be selected, of fresh 

 growth. They should be cut into short lengths, so as not to require 

 much acid to cover them, and treated exactly as the Deutzia leaves,^ 

 but they want a little more cooking. When finished they are quite 

 white, and in the state of hollow tubes, all their insides being eaten 

 out. To prepare for the Microscope, a piece of the tube must be slit 

 open and flattened out on a slide with fine needles in a drop of water. 

 If it curls up it must be flattened again and kept so by a cover-glass. 

 When quite dry, mount in balsam, and view with a 1-2 inch objective, 



* Jouru. Quek. Micr. Club, i. (1883) p. 241. 

 t Knowledge, iv. (1883) pp. 130-1. 



X The remarks above quoted are preceded by a description of the method of 

 treating the leaves of Deutzia scab a, 



Ser. 2.— Vol. III. 3 Q 



