TRESH-WATER TROUT-VARTETTES 01'\ 183 



varieties of the trout, asserted Salmo fario, S. h-mcums, h>. rappii, and »S'. Incii.'ilris, 

 of Lake Constance all belong' to one form which ho jn-oposcd terminer S. variahihs. 

 Steindachncr {Ak. Wiss. Wien, Hi, 18G5, Nov. 3Uth) identified >S'. delcx, lEeck 

 with S. fario. Pavcsi {Vesci nel Ticino) considered the lake and river trout ot 

 the river Canton to be merely varieties of one species. Eatio observed, " Our 

 fresh-water trout, according as it is more or less conlined to small streams or 

 to the deeper waters of our lakes, presents an appearance so different as to have 

 passed hitherto for two perfectly distinct species in the eyes of most ichthyolo- 

 g-ists. It is well known that the size of the basin and the relative abundance of 

 food* have much influence on the dimensions of the fish. The little brook trout 

 which most zoologists still distinguish under the name of Sahno ausonii, is in 

 fact, in my opinion, nothing more than a form of the great trout of our lakes, 

 which is called according to circumstances TriUta lacustris, T. scMffcrviiUlcn, 

 Fario marsigUi, or Salmo lematms. Most of the characters proposed for its 

 distinction are those of the early age of the fish. In a small stream the trout, 

 which cannot grow for want of room, arrives at an advanced age, retaining more 

 or less the characters of infimcy. It would be still more surprising to meet with 

 trout of 30 lb. in a few inches of water." 



Perhaps it will be as well to here refer to the eggs of the fresh- water trout, 

 which have been forwarded to, and been the progenitors oi the species in Austral- 

 asia, and it will be exceedingly important to clearly follow this out, as attempts 

 have been made to show that they may be hybrids.f The origin of these fish 

 were due to Frank Buckland having at Admiral Keppel's request collected I2U0 

 ova from his preserves on the Itchen, and forwarded them as a present from him 

 to Mr. Youl. Mr. Francis Francis also sent two lots, about 800, from Mr. Spicer s 

 mill at Alton-on-the-Wey, and about 700 from Mr. Thurlow's mill at High 

 Wycombe, Buckinghamshire, and all were packed and dispatched by Mr. Youl.J 

 No subsequent shii)ment of fresh- water trout ova has been successful, at least up to 

 the date of Mr. Nichols' work. These original eggs arrived at the breeding ponds 

 in Tasmania, on April 21st, 1864. The first successful trout hatching m Otago, 

 New Zealand, ]\Ir. Arthur reported, occurred in October, 18G8, from 800 ova 

 obtained from the natural spawning beds of the brook trout, Salmo fario, m 

 Tasmania ; these and a second lot, the subsequent year, formed the whole of the 

 original stock, some of which were first liberated in the streams m November as 

 was also vouched for by Mr. Allport in the Proceedings of the Zoological Societi/ 



Unless all these gentlemen have been mistaken, it is abundantly clear that the 

 original stock of fresh-water trout in New Zealand came from Tasmania, and 

 were descendants from those raised from the eggs sent out by Mr. Youl. And 

 now comes the inquiry have these fishes retained the exact characters of those 

 from which they were sprung, or have new surroundings developed differences ? 

 The late Mr. Arthur, C.E., who took so warm an interest in the trout, informed 

 us that in New Zealand they spawned from about the middle of June to the 



* Professor Forel, Nature, 1886 (p. 195), m-iting of the fauna and flora o Lake Lcman, 

 observed that the principal agents affecting life in the lake are temperature and hgUt, ot less 

 importance are the shape and capacity of its basin, the matters dissolved in or held in suspension 

 by its waters, and the movements (for the most part superficial) to which its waters are subject. 

 Light is a far more important feature than temperature. It is at a depth of 30 metres or where 

 chlorophyle-forming vegetation ceases, that he separates the littoral from the deep regions of the 

 lake ; the actinic action of light ceases, at 50 metres in summer and at 100 metres only in winter 

 when the water is more transparent. In the deep region aU tends to calm, rest, and absence 

 of movement, uniformity, monotony, equality, no motion, no variation, and characters only 

 comparable with those of the deep sea. The population is denser in the upper part of the deep 

 region than it is in the lower, but even in the deepest part life is present. The greater part ot 

 the species, invertebrates, are evidently the descendants of the inhabitants of the shallow waters, 

 and differ from them chiefly in being smaller and less brightly coloured ; the eyes are wanting in 

 Giirator coccus, and have a tendency to disappear in other species. t • m 



t " As it is a fact that numerous cross-breeds have been introduced into, and reared in iasmania, 

 which must more or less interfere with the characters of the pure breeds Gunther, Intro- 

 duction to the Study of Fishes, 1880, p. 642. See also Mr. Nichols' work on The Acchmatisation 

 of the Salmonida at the Antipodes, ISS'2. _ , • -.or-, i-n i ,, i^n 



t See letter by Mr. Youl to The Fisherman's Marjazine and Ecview, vol. i, 1804, eutilled \V ho 

 sent the trout ova to Tasmania " (p. 429). 



