. 
496 — NATURAL HISTORY MISCELLANY. 
ryos, now ready to burst the shells of the eggs, extend thelr tails, make 
light oscillations with the fan and its appendages, so as to grad- 
ng lobsters, which it succeeds in doing in a aed days. 
Phe maei recia as soon as born, swims away from its parent, rises 
to the surface of the water, and leaves the shores for the deep waters of 
the sea, where it passes the earliest days of its existence, in a vagabond 
state for a period of from thirty to forty days. During this time it under- 
goes four different changes of shell, but on the fourth, it loses its natatory 
organs, and is therefore no longer able to swim on the surface of the 
water, but falls to the bottom, where it has to remain for the future; ac- 
cording, however, to its increase of size, it gains E w approach the 
shore, which it had left at its birth. The number of e es which assail 
the young embryos in the deep sea is enormous, thousands of all kinds 
sary condition to their rapid growth. In fact, every young lobster loses 
and remakes his crusty shell from eight to ten times the first year, five to 
seven the second, three to four the third, and from two to three 
fourth year. However, after the fifth year, the change is on nly annual, for 
ar 
hen it begins As aneo and from this period the gro 
more gradual.” —R. K. Woop, in Land and Water, London. 

A GEOLOGY. 
WHAT IS A GEODE?—The term geode is applied by geological writers 
to two distinct conditions Da character of rocks, in so promiscuous a 
manner that the reader, without specimens, has no o means by maa 
determine, with any degree of certainty, pe it is of which the writer 
treating. Let me illusitáte by numbered exa 
they occur, and in no way EO a it, “the cavity being * 
mere opening in the general mass of the foundatio nclosed 
No. 2. Rounded masses of penta, often Chakassen, riir oii 
in limestone, etc., but as foreign in character, from t the eral ene peen 
them, as raisins are to the mass of a pudding by ok ae have 
e rock containing these takes piace, these balls f 
where they remain wholly unattacked by the elements 
These silicious nodules vary in size from that of an ap 
E E 
ple to that of 




