Journal of 



Applied Microscopy 



and 



Laboratory Methods 



Volume V. MARCH, 1902. Number 3. 



Laboratory Equipment for Beginning Course in Zoology. 



The question of a suitable equipment for large laboratory classes in elemen- 

 tary zcolog)' is often a most serious and perplexing one. Not only is it difficult 

 to find the pieces of apparatus already made, but even when purchasable, the 

 attendant expense makes them unavailable in many cases where large numbers 

 are required. In nearly every laboratory these difficulties have been met and 

 solved more or less satisfactorily, usually by designing such apparatus as can be 

 made in local shops. Fortunately, the requirements of such elementary courses 

 are not exacting, and the improvised apparatus may serve as well as the most 

 expensive sorts. In many cases, even, the pieces are more directly suited to the 

 work required of them than are any that may be bought. 



Such a set for the individual student, evolved in actual practical work, is 

 described here. Aside from dissecting pans and instruments, it consists of two 

 pieces ; one, an easel ; the other, a standard for the support of lenses, etc. The 

 easel is merely a piece of soft pine or poplar board 5 x G x y^ inches, supported 

 behind by a piece of bent wire attached by small staples. Crude and simple as 

 this is, it ensures better work from the student at a much less degree of personal 

 discomfort than is otherwise possible. Since the style of drawing usually required 

 of beginners is that known as orthographic projection, it becomes necessary to 

 view the specimen from directly above each part drawn. If no support is pro- 

 vided, the student either lays the specimen upon the table and endeavors 

 to look down upon it, or he props it against books or other objects so that it may 

 be observed more easily. In either case the process is time consuming ard 

 troublesome. 



By the use of the adjustable easel, much trouble and eye strain is avoided. 

 The specimen, a crayfish for example, is pinned to the board against a suitable 

 shade of paper for a background, the appendages are arranged and secured to 

 the board, which is then erected at such an angle that the line of sight falls upon 

 it normal to the surface. In this position the animal is well lighted, is easily 

 measured, and the tendency to introduce perspective in the drawing is minimized. 



(1677) 



