THE GREAT DEEPS 133 
the Antarctic. The male sea-spiders from 
the deep sea, like those from shallow seas, 
carry the bunches of eggs attached to their 
limbs. It is also interesting to find that some 
animals, whose seashore representatives lib- 
erate eggs, bring forth embryos in the Deep 
Sea. This is probably an adaptation which 
counteracts the risk of the passive eggs being 
smothered in ooze. 
RETROSPECT 
Let us now gather together briefly what we 
have learned, and try to make a mind-picture 
of the depths of the ocean. 
The average depth is 214 miles, but there 
are “deeps” of over 6 miles, so that the 
highest mountain in the world, if thrown 
in, would be far below the surface of the 
water. 
It is very cold; it is absolutely soundless; 
it is calm, and quite dark, save for the weird 
blue-green light radiating from the corals 
fixed in the mud, or from the luminous spots 
of the animals slowly moving in and out 
among these “ perpetual light-houses.” Star- 
fishes, sea-urchins, sea-cucumbers, many kinds 
