■614 



ANATOMY OF VERTEBRATES. 



427 



S9- 



into their nursery when clanger threatens.' In Syngnathns 

 ophidion the male carries the eggs under the flat abdomen in cells 

 placed lengthwise in three rows.^ In the 

 male Hippocamp the marsupium is subcau- 

 dal, opening by a vertical fissure just below 

 the vent.' In the Holconoti the young ac- 

 quire full developement, perfect gills, and a 

 size one third that of the parent, before 

 quitting the ovarian marsupium.'' 



Both Salmon and Trout excavate the 

 gravelly bed which they select for spawning ; 

 and the ova may be found from one to two 

 feet deep in this stony nest. The Stick- 

 leback (^Gasterosteus aciileatus) fabricates a 

 more artificial nest. Aristotle signalises the 

 Plnjcis, since recognised as a Mediterranean 

 sjiecies of Gohhis, as the only sea-fish that 

 makes a nest and deposits its spawn therein. 

 Olivi confirmed the statement, and describes 

 the nest as being composed of sea-weeds 

 (alga3 and zostera), adding that the male fish 

 guards the female during the act of oviposi- 

 tion, and the young fry during their deve- 

 lopement.^ 



Dr. Hancock has observed similar habits 

 in certain fresh-water Siluroid Fishes of De- 

 merara called ' Hassars,' which belong to the 

 genus CalUclitlnjs : the Kound-hcaded Has- 

 sar forms its nest of grass ; the Flat-headed 

 Hassar of leaves. ' They are monogamous : 

 both male and female remain by the side of 

 the nest till the spawn is hatched, with as 

 nivich solicitude as a hen guards her eggs, 

 and they courageously attack any assailant. 

 Hence the negroes frequently take them 

 by putting their hands into the water close 

 to the nest ; on agitating which, the male 

 Hassar springs furiously at them, and is 

 ,ihiis thus captured.''' 



§ 117. Fcciaidafion of Ilcptilcs. — Sala- 

 Frogs, and Toads arc generally apt for breeding 



Eckstroem (1831), quoted in xxxix. ii. p. 327. 



XX vol. V. p. 67, prep. no. 322y. " lb. no. 3223. * cccxxxv. 



SXiii. t. xii. p. L-. " cccxxvi. p. 244, 



Marsiuilnl piui. 



mandcrs. Newts 



