1 62 Life and Immortality. 



the rearing of their submarine castles are ordinarily sub- 

 jected to a swift current, the largest stones, which it would 

 be thought impossible for them to move, are looked for up 

 stream. A suitable one found, and a favorable position pre- 

 sented, the sucking mouth is fastened to it, and by a con- 

 vulsive effort, the tail of the fish being raised aloft, the heavy 

 stone is lifted from its place, the current pushing against the 

 fish and stone, bearing them along several feet before they 

 sink. Another effort of the fish, and the rock is again raised 

 and carried down stream, until finally, by repeated liftings 

 and struggles, the ingenious, persevering nest-builder is swept 

 down to the nest, where the load is deposited. This labo- 

 rious work is carried on until the pile has attained a height 

 of two or three feet, and a diameter of four. No special form 

 seems to be necessary. The nest is generally oval, compact 

 and well devised to contain the eggs, which are carefully 

 deposited within, thus affording protection in its numerous 

 interstices for the young when they hatch. When about six 

 inches long, the young Petromyzon marinus, which is a strange 

 little fellow, is devoid of teeth, and blind, and possesses so 

 many characteristics distinct from the parent, that for a long 

 time he was considered a separate species, and even assigned 

 a place in a different genus. Enormous nests are sometimes 

 built. John M. Batchelder, Esq., describes one, which he 

 saw in the Saco River, Maine, that was about fifteen feet 

 long, and from one to three feet in height, its position and 

 triangular shape in vertical section being well adapted for 

 securing a change of water, and a hiding-place for the young. 

 The operation of building was very methodical, a hundred 

 and more Eels being at work upon the structure. Water- 

 worn stones, chips of granites and fragments of bricks, some- 

 times weighing as much as two pounds and transported by a 

 single individual, were utilized in the building. 



More remarkable, however, than any previously described, 

 are the nests of the Fresh-water Chub, Semotilus bullaris, 

 which is known in some localities as the Stone Toter. 



