20 THE SEA-SHORE 



small indeed. Each is *no bigger than a tiny 

 pin's head. Instead of having shells, however, 

 these eggs have tough but very elastic skins; 

 and these skins are made in such a way that 

 while they allow water to soak in from- the out- 

 side, they will not allow it to pass out again. 

 So as soon as the eggs are dropped into the 

 sea they begin to swell; and the result is that 

 before very long each egg is as big as a good- 

 sized pea. 



If you pick up a cluster of these curious eggs 

 in the early spring and open them, you will find 

 inside each the shell of a very tiny whelk, which is 

 almost ready to hatch out. 



PLATE IX 



THE DOG WHELK (i) 



If you look in the ridges of small pebbles and 

 bits of broken coal which you will meet with 

 here and there on the sandy parts of the sea- 

 shore, you are quite sure to find a number of 

 very small whelk shells. They are brownish 

 yellow outside, and pinkish white inside, and 

 instead of being quite smooth, like those of the 

 common whelk, they are covered with a num- 

 ber of ribs which run down from the peak to 

 the margin. And these ribs are broken up in 



