vi THE DOMESTIC LIFE OF ANIMALS 117 



We do not know why the males among many fishes 

 are so much more careful than the females. For the 

 stickleback is not alone in his excellent behaviour. The 

 male Chinese macropod (Poly acanthus) makes a frothy 

 nest of air and mucus, in which he places his mate's eggs. 

 He, too, watches jealously over the brood, and " has his 

 hands or rather his mouth full to recover the hasty 

 throng when they stray, and to pack them again into 

 their cradle." Of all strange habits, perhaps that is 

 strangest which some male fish (e.g. Arius] have of hatch- 

 ing the eggs in their mouths ; 

 what external dangers must have 

 threatened them before this 

 quaint brooding chamber was 

 chosen ! Or is it not almost like 

 a joke to see the male sea-horse 

 swelling up as the eggs which 

 he has stowed away in an ex- 

 ternal pocket hatch and mature, 

 ' till one day we see emerging 

 from the aperture a number 

 of small, almost transparent 

 creatures, something like marks 

 of interrogation " ? But some 

 female fishes also carry their 



/ 



eggs about, attached to the ven- 

 tral surface (in the Siluroid fish, 



A n j \ , I (From Evolution of Sex ; af- 



Aspredo), or stowed away in a ter Atlas of Naples station.) 



ventral pouch (in Solenostoma, 



allied to pipe-fishes), arrangements which recur among 



amphibians, but on the dorsal surface of the body. 



A very remarkable adaptation securing the safety of 

 the eggs has been described in Kurtus gulliveri, a small 

 freshwater fish in New Guinea. The eggs are surrounded 

 by coiled filaments closely wound, like the india-rubber 

 thread in the core of a modern golf-ball. When they 

 arc laid the filaments uncoil automatically and the eg-gs 



J c">O 



are bound together in a double bunch, like a double 

 bunch of onions. At the same time on the top of the 

 male's skull a small bony process, like a bent finger, 



FIG. 34. SEA-HORSE 

 (Hippocampus guttulatus). 



