1897 THE MICROSCOPE. 113 
The first stomach is prepared by cutting it the whole 
length, then washing it thoroughly and taking off all the 
material as well as the mucous, which it contains with 
the pincers. It is then stained in carmine and mounted 
in glycerine jelly. 
To prepare the gizzard is a little more difficult because 
of its small size in most cases. The part is held by small 
pincers with one hand while with the other a needle is 
introduced in the direction of the axis. IJtis then turned 
lightly between the fingers. The gizzard being thus 
pierced, it is cut into upon the side to open it, then it is 
spread out and the interior carefully washed, as it is 
generally covered with debris of different kinds. The 
muscular envelope is then detached from the chitenous 
part by drawing it away withsmall pincers. Thisis then 
spread out, dehydrated in absolute alcohol and placed in 
essence of lavender—then mounted in Canada balsam. 
The use of potash is here useless and if the chiten is too ° 
soft, an immersion for a little while in essence of laven- 
der is sufficient. 
The gizzards of insects are extremely interesting to 
study, and among entomologists, those who occupy them- 
selves with the study of these insects with regard to their 
uses to nature come to know the internal structure of 
these organs and often get much information from the 
study of them. 
Sponge Spicules.—Some years ago I put up a number 
of slides of calcareous sponge spicules, using oil of cloves 
to displace the air from the spicules, and in turn replacing 
the oil of cloves by running in balsam in benzine. From 
these slides the spicules have completely disappeared, 
having evidently dissolved in the balsam, which would, 
perhaps, retain a trace of the oil of cloves.—Tuos. STEEL, 
Sydney. May 11, 1896. 
