SALMONID^E. 103 



streamlet possesses a breed peculiar in outward appearance to itself." Lord Home 

 (Yarrell's Fishes) observes of two streams, tlie Whitadder and its tributary the 

 Blackadder, that the first flows along a very rocky and gravelly bed, while the 

 latter rises in mosses, also goes through them in the first half of its course, but 

 subsequently along a rich and highly cultivated district. The trout in the first 

 are silvery in colour : while those from the Blackadder are dark with orange 

 fins. The many varieties are dependent upon external causes and chiefly to the 

 abundance or the reverse of food and the nature of the water they reside in, the 

 soil over which it flows, and other causes already treated of (pp. 57, 58). 



That this conclusion is based upon proof may be demonstrated by the result 

 of what has become of the progeny bred from the brook-trout eggs taken in 

 Hampshire or Bucks, by Buckland or Francis, and transmitted in 1866 to 

 Tasmania, some of which have become great lake-trout. Mr. Arthur (Trans. Otago 

 Institute, July 9th, 1878) tells us that unlike the Scotch trout which according to 

 Stoddart show a yearly increase of about one-third of a pound in weight,* in 

 Otago they grow so rapidly and are so fat that they have reached an average 

 yearly increment of from 1 lb. to 2 f lb. Already the various streams have stamped 

 the trout with local peculiarities : in some they are plump almost to deformity ; their 

 proportions are not constant neither are their colours. He tells us that examples 

 were said to have been seen up to 201b. in weight. This year, 1882, one 31 inches 

 long and weighing 19 lb. was caught at Temuka, its flesh was of a pale orange : last 

 year Mr. Grwatkin captured one in Canterbury, that turned the scale at 21 lb. The 

 foregoing facts corroborate my views that all our forms of trout are varieties of 

 one species, and the so-called hybrids are not mules but mongrels, being the 

 result of the crossing of varieties. Consequently, sterility need not be anticipated ; 

 but, on the contrary, improvement is more likely to ensue (should there be no 

 deficiency in food) than when the stock is bred in and in. 



It also tends to show that where small, but not malformed, breeds of trout 

 exist, riparian proprietors had far better investigate the condition of the food- 

 supply and nature of the waters in their streams than rely upon the introduction 

 of larger races. For, sooner or later, new stock will become indistinguishable from 

 the original local breed in colour, form, and size. 



Hybrids. — That hybrids exist among the Salmonidse and can be artificially 

 produced by the pisciculturist, f I have already pointed out (p. 59). It was with 

 much interest that I received in July, 1882, from Sir Pryse Pryse an undoubted 

 hybrid between the brook-trout and the American charr (Salmo fontinalis). The 

 example was 9 inches long, having the number of rows of scales descending to the 

 lateral-line intermediate between the two forms; the fins similarly modified, while 

 a row of teeth passed in an irregular manner along the body of the vomer. The 

 organs of generation were undeveloped, the example for this season at least was 

 certainly sterile ; some American charr of about the same size, received a few days 

 subsequently from Howietown, had the eggs and milt in a forward condition. 



Names. — Aller-float or aller trout, this refers to a large one frequenting a hole 

 in a retired or shady portion of a brook under the roots of an alder tree. In 

 Herefordshire there is a country proverb respecting the " aul " or " alder :" 



" When the bud of the aul ia as big as a trout's eye 

 Then that fish is in season, in the river Wye." 



* " A correspondent of the New Sporting Magazine, for November, 1840, observes that a friend 

 of his has kept trout in a kind of store stream, and having fed them with every kind of food, has 

 had some increase from 1 lb. to 10 lb. in four years. Mr. Toomer placed a trout of 3g lb. which he 

 caught in the river in a stew, and in about four years it had grown to about 9 lb." (Daniel, Kural 

 Sports). At Howietown, a Loch Leven trout hatched in 1875 weighed over 8 lb. in October, 1882. 



■\ At Sir J. Gibson-Maitland's, November 14th, 1882, I was given a living hybrid 11 inches 

 long, it was the produce of a Loch Leven female milted from a salmon on November 25th, 1879, and 

 hatched in 1880, consequently nearly three years old, in fact a sterile grilse. 1250 living parrs in 

 the boxes up to 4 inches in length, were the produce of 20,000 eggs of Loch Leven female trout 

 milted from the salmon, December 24th, 1881, and hatched March 9th, 1882. Their dorsal fins had 

 the anterior white edge usually seen in the brook-trout. One had 78 cojcal appendages, a second 61. 



