4 ACANTHOPTERYGII. 



denticulations. Professor L. Agassiz having most kindly supplied me with 

 examples from the Cambridge, Mass. Museum, from which Professor Garman has 

 selected five of the form P. flavescens with very great discrimination ; they 

 afford the following results, D. 13-14, | T ^, A. T ? T , L. 1- 55, 60, 65, 70; L. tr. 

 6-8/15-18. Length of the head 3|- to 3-§, height of body varies from 3 to 4 in the 

 total excluding the caudal fin. The radiating striaa on the summit of the head 

 are entirely absent in some but very distinct in others, and the same remark applies 

 to those on the opercle. In one the opercular spine is blunted, while the lower 

 edge of that bone is roughly crenulated : 1, 2, or 3, small spines are directed 

 backwards in three of these five examples ; in the last this edge is quite smooth. 

 Along the lower limb of the preopercle are from 6 to 11 forwardly directed 

 denticulations. Thus the radiating strias on the head as well as the denticulations 

 are so subject to variety in the American forms that no specific value can be 

 attached to them. The height and strength of the dorsal spines and rays vary, 

 the weakest being the most elongated : while, as a rule, the more elongated the 

 form the more pointed is the snout. Colour again is evidently of no specific 

 value, two of these five examples have no transverse bands : two have 8 bands, 

 and one has 7, irrespective of which they are either wide or narrow, well defined, 

 or else between them are numerous spots or blotches. The spot on the dorsal fin 

 likewise varies, and may be entirely absent. The form of the snout is similar to 

 that of P. fluviatilis, or else more pointed. Holbrook long since pointed out that 

 P. gracilis was a variety of P. flavescens, while Steindachner in 1878 remarked 

 upon its specific identity with the European perch. 



Varieties. — As to form, Linnaaus refers to a distorted perch having a hunched 

 back, found at Fahlun, in Sweden, where it is termed "Rudaborre :" Pennant 

 observes that similarly malformed ones exist in Llyn Rhaithlyn, in Merionethshire. 

 Pennell has likewise recorded similar fish in Cheshire, and they have been taken 

 in other localities. As to colour — Cuvier has described examples in which the 

 dark transverse bands were absent : some have been observed almost white : and 

 others of a slatey-gray having a silvery tint. These variations in colour are 

 perhaps due to the soil in which the waters exist where these fish were bred, but 

 may remain even if transported elsewhere. One example, 18 inches long, and 

 weighing 4| lb., was captured in 1866 near Great Yarmouth, in Ormesby Broad, 

 with the transverse bands scarcely distinguishable, and the succeeding year 

 one of 2 lb. weight in Virginia Water, which was quite destitute of any bands. — 

 (Zoologist). 



The name of this fish is of Greek origin, signifying " dark colour," which 

 probably refers to its bands, while this nomenclature has been introduced with 

 but little change into almost every European country. It is the perca of the 

 Romans, the perch of the British Isles, perc, Welsh : the old Anglican, hears, 

 Dutch, baars, German, barsch, or the "banded fish," bors or pertsh. La perche, 

 French. The word perch formerly was spelt pearch. This fish possesses certain 

 local or provincial names, as barse in Westmoreland, or if young hurling : base, 

 Cumberland : trasling, Cheshire ; crutchet, Warwickshire. Likewise those of one 

 season are termed tranling, of two seasons egling, if of three stichling. 



It has been very truly observed that in referring to the local names of plants 

 as given by old authors, one should not lose sight of the fact that strict exactitude 

 will not always be found, so it is also in fishes, for as in this day some persons 

 term all small fresh- water forms "minnows" or "gudgeons," and all minute 

 marine ones " sprats ;" so our ancestors were not more particular than many 

 authors belonging to the present generation, and who are neither fishermen 

 nor naturalists. Thus the same name became applied to quite different species of 

 fish while the same fish might have twenty distinct designations. The Saxons 

 have represented one of their gods standing on the back of a perch with naked 

 feet, as an emblem of patience in adversity and constancy under trial. 



Habits. — Perch as a rule are gregarious fresh- water forms, which inhabit 

 lakes, ponds, and rivers, more especially frequenting deep holes or where there is 

 a gentle current, preferring the sides to the more rapid parts of streams. 

 Occasionally they descend to salt water, and when found in such localities or 



