34 MR. F. DAT ON THE 



the greatest vigilance, driving away any interloping fish ; and at 

 the end of a month numerous fry appear, over which the old 

 Gouramies keep guard many days*. M. Carbonnier, who has 

 studied the habits of the Chinese Butterfly-fish (Macropodus) in 

 his private aquarium in Paris, where he had some in confinement, 

 observedf that the male constructs a nest of froth of considerable 

 size, 15 to 18 centimetres horizontal diameter, and 10 to 12 high. 

 He prepares the bubbles in the air (which he sucks in and then 

 expels), strengthening them with mucous matter from his mouth, 

 and brings them into the nestj. Sometimes the buccal secretion 

 will fail him, whereupon he goes to the bottom in search of some 

 confervse, which he sucks and bites for a little in order to stimu- 

 late the act of secretion. The nest prepared, the female is in- 

 duced to enter. Not less curious is the way in which the male 

 brings the eggs from the bottom into the nest. He appears 

 unable to carry them up in his mouth ; instead of this, he first 

 swallows an abundant supply of air, then descending, he places 

 himself beneath the eggs, and suddenly, by a violent contraction 

 of the muscles in the interior of his mouth and pharynx, he 

 exhales the air which he had accumulated by the gills. This air, 

 finely divided, partly by the lamellae and fringes of the gills, es- 

 capes in the form of two jets of veritable gaseous powder, which 

 envelops the eggs and raises them to the surface. In this 

 manoeuvre the Macropodus entirely disappeared in a kind of air- 

 mist, and when this had dissipated he reappeared with a multitude 

 of air-bubbles like little pearls clinging all over his body. 



In Asia there are several species of Snake-headed or Walking- 

 fishes (Ophioceplialus) . The male of the common striped form, 

 O. striatus§, constructs a nest with his tail among the vegetation 

 at the side of tanks, biting off the ends of the weeds that grow in 

 the water. Here the ova are deposited, the male keeping guard ; 

 but should he be killed or captured, the vacant post is filled by his 

 partner. It is a curious sight to see them with their fry swim- 

 ming aloug near the surface of the water, the latter generally 



* General Hardwicke, Zool. Journal, iv. 1829, p. 309. 



t Bulletin de la Societe d'Acclimatation, Paris, 1872. 



J The same fact has been observed of the Gasterosteus aculeatus by Mr. Mabel, 

 the Curator of the Weston-super-Mare Museum. 



§ Pristolepis malabaricus, which is not amphibious, constructs a nest accord- 

 ing to Mr. Thomas. 



