196 THE MICROSCOPE. 
Fig. 2 x 240. Vertical section through one side of the base of 
the same circumvallate papilla, showing the bottom of the trench 
and the four lowest tiers of taste-bulbs. ¢. b., Taste-bulb, the refer- 
ence mark indicating the apical end. 
Fig. 3x 40. Transverse vertical section through one of the 
papille foliate. 
_ Fig. 4.x 40. Horizontal section through the upper part of one 
of the papille foliate. st. m., Striated muscle-fibres which have 
been divided transversely to their long axis. 
Fig. 5 x 240. Vertical section through a fungiform papilla of 
the mid-dorsal region of the tongue, showing a single taste-bulb at 
its upper part. The two upper thirds of the bulb are embedded in 
the epithelium and the lower third rests in a depression of the mucosa. 
Fig. 6 x 240. Transverse vertical section through the lower 
part of the posterior surface of the epiglottis. 6., Bulb-like struc- 
ture,-entirely epithelial in position. 
Amuerst, Mass, . 
HISTOLOGY OF THE EARTHWORM. 
L. W. CHANEY, JR. 
[PLATE VIII.] 
HE earthworms are of special interest to the biologist for sev- 
eral reasons. Their simple and representative structure fits 
them for elementary study, and their economic importance, as shown 
by Darwin, gives them practical interest. As presenting many inter- 
esting histological details, they are attractive to the worker with the 
microscope. The preparation of them for microscopic study is a 
somewhat tedious process, but the result of patient manipulation is 
ample reward to the interested student. As in many of the lower 
animals, so here, the precautions necessary to a good preparation 
must begin in the killing of the animal. Several methods of killing 
and hardening have been tried, none, on the whole, giving better 
results than that recommended in Sedgwick and Wilson’s Biology. 
It is briefly as follows: The worms are placed in a shallow dish and 
covered to the depth of half an inch with water. Strong alcohol is 
then dropped, a few drops at a time, upon the surface of the water: 
This is repeated at intervals of five minutes, until the worms cease 
movement and lie easily extended. The process takes from three to 
five hours. Care is necessary that the process be not hurried at all, 
as undue haste causes a shrinkage of the tissues, which will be most 
aggravating when the section is viewed. The worms, thus carefully 
deprived of life, should be plump and straight. They should then 
be placed closely side by side in a dish, and covered with 50 per cent. 
