408 
APPENDIX. 
ney of the sheep. Several of these should be procured and 
opened in various directions to show the structure (Fig. 93). 
CHAPTER XYI. 
With little trouble skeletons of frogs, birds, and mammals 
with bones connected by flexible attachments may be prepared. 
Carefully cut away all of the muscles and other soft parts, leav¬ 
ing only the ligaments connecting the bones. Then place the 
roughly prepared specimen for one or two weeks in Wicker- 
sheimer’s fluid, which is prepared as follows: In three litres of 
boiling water dissolve 100 grammes of alum, 60 grammes of 
caustic potash, 25 grammes of salt, 12 grammes of saltpetre, 
and 10 grammes of arsenic. Cool and filter the liquid. Then 
to each litre of the fluid add 400 cubic centimetres of glycerine 
and 100 cubic centimetres of alcohol. The ligaments of skele¬ 
tons soaked in this fluid will remain flexible during many 
months of exposure to the air. Should the ligaments become 
stiffened, their flexibility may be restored by a few hours’ im¬ 
mersion in the fluid. 
CHAPTER XVII. 
Muscle fibres for microscopic examination may be obtained 
from the leg of a frog, or even from the body of a recently 
killed animal at the meat-shop. Lay a small piece of muscle 
in a drop of .75 per cent, salt solution on a glass slide, and with 
a pair of dissecting-needles carefully pick the muscle to pieces. 
Some of the smallest shreds, upon examination with a one-fourth 
or a one-sixth inch objective, will be seen to be single or 
grouped muscle fibres, which will show the striations and the 
sarcolemma (Figs. 11, 12). 
CHAPTER XVIII. 
Nerve fibres are readily obtained from the sciatic nerve in the 
