464 ZOOLOGY. 



PRACTICAL WORK. 



Two excellent works cover the practical work required 

 viz. Marshall's The Frog (David Nutt, 4s.), and Marshall 

 & Hurst's Practical Zoology (Smith, Elder & Co., 10s. 6^.). 

 Useful instructions are also given in Parker & Parker's 

 Practical Zoology (Macmillan, 10s. 6d.), and the figures in 

 Howes' Atlas of Biology (Macmillan, 14s.) are of great help 

 to a student working alone. The latter does not, however, 

 include rabbit, dogfish, or amphioxus among its types. 



The student who cannot attend a practical class regularly 

 is strongly advised to get some practical work done as early 

 as possible under the guidance of a teacher : he will then 

 be in a far better position to continue by himself. 



We confine ourselves here to such general advice as is 

 needed by a student working alone. The following instru- 

 ments are indispensable for practical work : 



(a) Two or three scalpels of various sizes. 



(b) Scissors, which must taper gradually, have straight blades, 

 and be pointed at the ends, and which must bite right up to the tips 

 (or they are useless). Two pairs, small and large, are advisable. 



(c) Two pairs of forceps, large and fine. Both should have the 

 inner surface of the tips roughened, and the points should meet 

 accurately. The fine ones may preferably be curved at the tips. 



(d) Two needles set in wooden handles. 



(e) A seeker, i.e. a blunt piece of wire, slightly bent near the tip, 

 and preferably mounted in a wooden handle. 



(/) Some sort of lens (magnifying glass). A watchmaker's glass 

 is very good, but the student is not advised to attempt learning how 

 to keep it in his eye by contracting the muscles of the orbit, he may 

 think he has learnt the trick, but it will only be to find that at the 

 critical point of a delicate dissection, his attention being concentrated 

 on his work, the glass will fall from his eye and spoil his work. An 

 elastic band made to fit the head will hold the glass much more 

 conveniently. 



(g] Pins of at least three sizes : ordinary ones, about an inch long, 

 for such types as the frog and crayfish; "baby" pins, half an inch 

 long and very fine, for earthworm and Amphioxus ; and stout laundry 

 pins or nails, one and a half inch long, for rabbit and dogfish (blanket 

 pins are too long and too easily bent : you want something you can 

 hammer on). 



(h) A board (an old drawing-board, or a packing-box lid) on to which 

 to pin the rabbit and dogfish. Failing this an old table will do. 



(i) A dissecting dish with either paraffin or cork to pin smaller 

 types on. A pie-dish will do very well, but something with vertical 

 sides is better. If you use paraffin it must be melted in the dish, 



