FISH AS FATHERS. 159 



This high-principled lophobranch is so careful of its 

 callow and helpless young that it carries about the 

 unhatched eggs with him under his own tail, in what 

 scientific ichthyologists pleasantly describe as a sub- 

 caudal pouch or cutaneous receptacle. There they hatch 

 out in perfect security, free from the dangers that beset 

 the spawn and fry of so many other less tender-hearted 

 kinds ; and as soon as the little pipe-fish are big enough 

 to look after themselves the sac divides spontaneously 

 down the middle, and allows them to escape, to shift for 

 themselves in the broad Atlantic. Even so, however, 

 the juniors take care always to keep tolerably near that 

 friendly shelter, and creep back into it again on any 

 threat of danger, exactly as baby-kangaroos do into their 

 mother's marsupium. The father-fish, in fact, has gone 

 to the trouble and expense of developing out of his own 

 tissues a membranous bag, on purpose to hold the eggs 

 and young during the first stages of their embryonic 

 evolution. This bag is formed by two folds of the skin, 

 one of which grows out from each side of the body, the 

 free margins being firmly glued together in the middle 

 by a natural exudation, while the eggs are undergoing 

 incubation, but opening once more in the middle to let 

 the little fish out as soon as the process of hatching is 

 fairly finished. 



So curious a provision for the safety of the young in 

 the pipe-fish may be compared to some extent, as I 

 hinted above, with the pouch in which kangaroos and 

 other marsupial animals carry their cubs after birth, till 

 they have attained an age of complete independence. 

 But the strangest part of it all is the fact that while in 



