LIMITATION IN LOWER VERTEBRATES 137 



together with a sticky secretion from the kidneys. When the 

 female has deposited her eggs in the nest, she deserts it, and the 

 male continues to guard nest, eggs and young fry with the 

 most pugnacious spirit. The larger stickleback of salt water has 

 similar habits, building a nest, in sheltered pools, of seaweeds and 

 plantlike colonies of hydroids. In 

 the brightly coloured marine wrasses, 

 both sexes join to build the nests, 

 which are constructed of broken shells, 

 seaweeds and other debris. The great 

 masses of gulf -weed forming the " Sar- 

 gasso Sea ' ' in the areas affected by 

 the Gulf Stream are a preserve for 

 marine creatures which drift about 

 in the protection of the weed. Amongst these, 

 the marbled angler (Antennarius marmoratus) , 

 a small fish that rests on the weed with almost 

 armlike pectoral fins, constructs a globular nest 

 supported by silky fibres, within which the 

 eggs are suspended in bunches. 



A few fishes reduce the number of the family 

 still further and protect it by carrying about 

 the eggs and young larvae. The well-known 

 sea-horse (Hippocampus) (Fig. 28), which carries 

 itself erect when swimming and looks like the 

 knight of a chess board, has a pouch in the 

 male, on the front of the body opposite the 

 root of the tail, and in this the eggs and 

 young larvae are carried about. The pipefish, 

 which is sometimes found amongst whitebait, pouch. (After MURRAY.) 

 has a similar pouch, which, however, is longer 

 and narrower, to suit the different shape of the body. In Soleno- 

 stomus, which inhabits the Pacific and Indian Oceans, there is a 

 similar pouch, but carried by the females, and formed of the ventral 

 fins. Most of the catfish protect their young by making nests and 

 guarding them with fury, more often the male, as Aristotle observed 

 in the case of the European catfish (Silurus glanis), but sometimes 

 the female, sometimes both sexes, performing this duty, and after- 

 wards herding the shoals of fry when they emerge. In a few cat- 

 fish the number of eggs is still further reduced, and the male or 

 the female, according to the species, carries them in the mouth and 



