PHILOSOPHY OF ZOOLOGY. 367 



catalogue had been more extensive ; we fondly hope that it 

 will soon increase. 



The formation of ponds for salt-water fish, has often 

 been the subject of speculation, but in few instances has it 

 ever been reduced to practice. Indeed the motives for con- 

 structing such a pond must originate chiefly in curiosity, as 

 those who are situate on a sea-coast, where such ponds 

 can only be constructed, have access to that great storehouse 

 of life, and may at all seasons derive from it an inexhaus- 

 tible supply. Besides, there are few situations favourable 

 for the construction of such a pond, and even where most 

 favourable, an expensive barrier must be constructed to se- 

 parate it from the sea. Some ponds of this kind have been 

 constructed in Scotland. These are well described by Mr 

 NEILL in the Scots Magazine for June 1816, p. 41 . * 



* " A good many years ago, a small fish-pond, into which sea-water could 

 be easily introduced, was constructed by an enterprising individual at Peter- 

 head, in Aberdeenshire, (Mr Arbuthnot). A few sea-fish were occasionally 

 kept in it ; but it soon fell into disuse, and it has of late been neglected. 

 This, however, was, as far as we know, the first attempt of the kind in this 

 country. 



" Since that time two sea-fish ponds, of greater dimensions, have been 

 formed by private gentlemen in Scotland, for the conveniency of supplying 

 their families. One of these is at Valleyfied, the seat of Sir ROBERT PRESTOX, 

 Bart., on the shore of the Frith of Forth ; the other is situate in Wigtonshire, 

 in an inlet called Portnessock, on the peninsular ridge of country called the 

 Rins of Galloway, nine or ten miles south from Portpatrick, and is the pro- 

 perty of Mr MACDOWALL of Logan. 



" At the spot where it is formed, there had originally been a small natu- 

 ral basin, communicating with the sea by means of a narrow sinuous fissure, 

 or perhaps an empty vein in the rock. This basin has been enlarged and 

 deepened, by working away the solid rock, which is grey-wacke slate. At 

 flood-tide, the water covers, to the depth of two or three feet, a ledge or 

 walk which passes round an interior or deeper pond, and, at this time, allows 

 tolerably ample space for the rapid motions of the fish. 



