THE SCHOOL OF THE SHORE 57 



keep till we come to the fresh-water haunt. 

 Less familiar is the case of a tropical shore-fish 

 (the Gaff Topsail), which has only a few eggs, 

 and lives in places where the struggle for 

 existence is very keen. What is it to do? The 

 male fish takes the eggs in 

 his mouth and keeps them 

 there until they are hatched. 

 One would think it must be 

 difficult not to swallow them, 

 but he fasts all the time. 



There are many other 

 examples of "love" on the 

 seashore. The marine leech 

 or Skate-sucker (Pontobdella 

 muricata), a warty green 

 animal, is both male and 

 female at once, like earth- 



worms and Snails. It is a FlG< 3- THE SKATE- 



SUCKER (PONTOB- 



very careful parent, deposit- DELLA). 



^ t . .A Marine Leech that 



ing the eggs in cocoons in- akes great care of 



side empty shells of bivalves, its 

 and mounting guard over them for many 

 weeks. It is interesting to find examples of 

 marked parental care on the lower rungs of 

 the ladder of life. One of the humblest illus- 

 trations is to be found in a British star-fish, 



