i8o 
ANIMAL ACTIVITIES. 
In a specimen which has been hardened in alcohol 
do you find vertebrae ? Do you find a notochord ? Do 
you find muscles like those in the fish ? Notice the 
spirally coiled intestine. 
Hold the tail of a living tadpole under a compound 
microscope and observe the movement of the blood. 
Notice the corpuscles. 
Summary of Drawings. ( a ) Side view of tadpole. 
( b ) Dorsal view of a young tadpole to show gills. 
(c) Sketch to show blood-vessels as seen under the 
microscope. 
The Frog Alive. How does the frog resemble the 
fish ? the tadpole ? 
Do you find scales, hair, claws, or nails ? 
Do you find tail or fins ? How about legs ? 
What is the frog’s mode of locomotion on land ? in 
water ? 
How many divisions have the hind limbs ? the fore 
limbs ? How do they compare with the limbs of the 
human body ? Do the joints move in the same way as 
ours ? Do you find arm, forearm, and wrist ? 
How many fingers ? How many toes ? Are fingers 
or toes webbed ? Do you find a thumb ? 
How does the frog take its food ? How does the 
tongue act ? 
What movements are made in breathing ? Are 
there any gills ? How long can a frog live under 
water ? 
Does the frog have the same senses and the same 
organs of sense as man ? 
Do you find ears ? eyelids ? Do you find a mem¬ 
brane covering the eye (nictitating membrane) ? 
Frog Hardened in Alcohol. Look in the mouth. 
Do you find any teeth ? How many ? Where are 
they ? 
What is the shape of the tongue ? 
Do the nostrils connect with the mouth ? 
. Does the ear-cavity connect with the mouth ? 
