an a! i, 
ANALYSIS OF HALL OF SHELLS. X1x 
its connection by strong muscle with the animal tested. 
Look up in an encyclopzedia how the cartilaginous air vesi- 
cles composing the egg float of the sea snail are secreted 
and how attached. 
CHAPTER VI.—The dip net brings up marvels un- 
dreamed of before ; the brine and mud become full of les- 
sons; hydroids, scalaria, stomapod, and Sapphirina give 
up their secrets. The sea bottom is shown by science to 
be more than a fairyland. A dip net may be used in study 
in either salt or fresh water. Read The Bottom of the 
Sea, by T. Sourel. 
CHAPTER VII.—The Physalia or Portuguese man-of- 
war is sometimes driven up from the tropic seas and 
stranded. It is one of the most interesting of the Meduse 
family ; armed with poison-filled tentacles which are its 
weapons of defense, and by them its food is obtained. The 
study of the Meduse, either in books or actual life, wateh- 
ing development, will fill many days with delightful em- 
ployment. In fresh water, common Hydra may be found 
under leaves of aquatic plants. Cut them in pieces and see 
their power of reproduction from the severed pieces. Turn 
them inside out and see the result. 
CHAPTER VIII.—Origin of pearls was formerly ac- 
counted for by drops of dew becoming solidified. Pearls 
are formed over hard, offensive matter within the folds of 
the mantle, also secreted and used as nacre by the animal 
in mending points of irritation. Pearls most highly 
esteemed by all nations and at all times. Pearls are of 
various colors and each color has its peculiar votaries. 
The pearl Cleopatra drank questioned by science. 
The rainbow shells of the Haliotide called Awabi in 
Japan, abalone in California. The iridescence of their 
nacreous lining due to the laminations of nacre secreted 
by the animal and irregularly overlapping in delicate 
films. Read Precious Stones, by Harry Emanuel. 
CHAPTER IX.—Term Alge now includes much less 
than formerly, many specimens once held as vegetable 
