FISH AND THEIR NESTS 41 
by himself in the nest during the two days I 
observed him, and was occupied chiefly in 
smoothing down the sides of the excavation ; 
this he did revolving round and round with 
his tail in the centre, brushing away dirt from 
the sides of the nest with his fins. On the 
third day I returned early to the nest and 
found it unoccupied. A short distance away, 
however, the same male was to be seen, now 
accompanied by a female.” 
In the Aspredo catrachus , also a member of 
the cat-fish family, the under surface of the 
female’s body becomes very soft and spongy 
during the spawning season. After laying 
her eggs, she presses upon them with the 
soft part of her anatomy so that they 
adhere to her body, in which situation they 
remain until the young ones are hatched 
out. 
The habits of the mailed tube-mouths 
( Solenostoma ), the pipe-fish of the genus 
Syngnathus , and the sea-horse (Hippocampus), 
are quite as extraordinary as those of any fish 
we have so far reviewed, for the creatures 
carry and incubate their eggs within the 
shelter of abdominal pouches. With the 
female of the former genus, the edges of the 
pelvic or breast fins unite with the skin of 
the under surface of the body, thereby con- 
