MR. TUFFEN WEST ON THE FOOT OF THE FLY. 419 
It may be desirable to add a few words on the best plan of conducting observations 
on these parts. Their action should be studied in living insects under the influence of 
chloroform, careful notes being taken of anything which may appear noteworthy, and 
accurate drawings prepared from the life as well. It is of the greatest advantage to pre- 
serve carefully all the parts that are examined ; for this purpose Deane's hum Hum or 
glycerine jelly suits exceedingly well ; some of the very delicate preparations, however, 
can only be kept satisfactorily in a solution of chloride of zinc. The old plan of soaking 
in caustic potash, crushing, washing, putting into spirits of wine, (or pressing and drying 
first, and) then into turpentine, and lastly into Canada balsam, is perfectly useless, except 
in rare instances where points connected with the structure of the integument have to be 
made out. Of course the parts should be viewed from above, from below, and in profile, 
in order to gain exact ideas of their relations. The binocular microscope, however, promises 
to diminish vastly the difficulties which had until quite recently to be encountered, as 
by its use the parts may be clearly viewed, just as they are, without preparation of any 
kind. 
EXPLANATION OP THE PLATES. 
Plate XLI. 
DIPTERA. 
The figures represent the feet of different flies as named :-o indicates the view of the parts on their 
under surface ; b, the same on their upper surface; c, profile view. - The foot represented is always that 
of the anterior leg, on the left side, unless it is otherwise distinctly stated ; the sex of the insect, when 
certainly observed or known, is also mentioned. R is used for a leg of the proper right side; L, of the 
proper left side : 1, 2, 3, for the anterior, middle, and hind legs respectively. 
Fi 
*g- 
1. Blow-fly (Musca vomitoria), $ 
Fig. 2. House-fly {M. domestical), $ : 
Fig. 3. Baker- fly (Sarcophaga) : L 3. 
Fig. 4. Drone-fly (Eristalis tenax). 
Fig. 5. Asilus crabroniformis, $ : L 3 
Fig. 6. Gad-fly {Tabanus bovinus), $. 
Fig. 7« Rhagio scolopaceus. 
Fig. 8. Echinomyia grossa. 
Fig. 9. Volucella plumata. 
Fig. lo. Scatophaga ster cor aria, 2,. 
Fig. 11. Syrphus balteattts, $. 
Fig. 12. Sargns cuprariits, $. 
Fig. 13. Bibio Marci, 2. 
Fig. 14. Borborus eguinus. 
Fig. 15. Piophila casei. 
Fig. 16. Ephydra riparia. 
Fig. 17. Midge (Psychoda). 
Fig. 18. Sheep-tick. 
Fig. 19. Hippobocide fly. 
VOL. XXIII. 
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