STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA., 15 
Lastly, the mollusca exhibit the same instinctive care with 
insects and the higher animals in placing their eggs in situations 
where they will be safe from injury, or open to the influences 
of air and heat, or surrounded by the food which the young 
will require. The tropical bulimi cement leaves together to 
protect and conceal their large bird-like eggs; the slugs bury 
theirs in the ground; the oceanic-snail attaches them to a 
floating raft; and the argonaut carries them in her frail boat. 
al : 
= ee EEE 5 = = 5 aes = 
Ne oom, COURT ane 
/ ie Zz S)}) 
Fie. 9. Janthina with its raft. 
The horny capsules of the whelk are clustered in groups, with 
spaces pervading the interior for the free passage of sea water ; 
and the nidamental ribbon of the doris and eolts is attached to a 
rock or some solid surface from which it will not be detached by 
the waves. The river-mussel and cyclas carry their parental 
care still further, and nurse their young in their own mantle, 
or ina special marsupiwm, designed like that of the opossum, 
to protect them until they are strong enough to shift for 
themselves. 
If any one imbued with the spirit of Paley or Chateaubriand, 
should study these phenomena, he might discover more than 
the ‘‘ barren facts’ which alone appear without significance to 
the unspiritual eye; he would see at every step fresh proofs of 
the wisdom and goodness of God, who thus manifests His great- 
ness by displaying the same care for the maintenance ot His - 
feeblest creatures as for the well-being of man and the stability 
of the world. 
STRUCTURE AND PHYSIOLOGY OF THE MOLLUSCA. 
Molluscous animals possess a distinct nervous system, instru- 
ments appropriated to the fiye senses, and muscles by which 
they execute a yariety of movements. They have organs, by 
which food is procured and digested; a heart, with arteries 
and yeins, through which their colourless fluids circulate; a 
