Nautilus and Ammonite. 129 
with from the surrounding fluid, give the desired 
onward motion, and away the swimmer goes, his 
long arms gathered closely together, and streaming 
behind like the tail of a comet, and its round eyes 
keeping a sharp look-out on either side. Should it 
espy danger, the body and limbs are withdrawn 
into the shell, and the fiuid driven through the 
central tube, so as to compress the air in the pearly 
cells, and down sinks the swimmer once again to 
his native depths, where 
“The floor is of sand like the mountain drift, 
And the pear! shells spangle the flinty snow; 
And from coral rocks the sea-plants lift 
Their boughs where the tides and billows flow. 
The water is calm and still below, 
For the winds and waves are absent there; 
And the sands are bright as the stars that glow 
In the motionless fields of upper air. 
And life in rare and beautiful forms 
Is sporting amid those bowers of stone, 
And is safe, when the wrathful spirit of storms 
Has made the top of the waves his own.” 
On the following page we give two figures of the 
Argonaut, one of which represents him crawling at 
the bottom of the sea, and the other swimming on 
the surface. 
