PERES K I A PERSIC A. 



423 



first and last rays spotted with black; the second 

 dorsal and pectoral J'ms pale brown ; ventral, anal, 

 and caudal tins bright vermilion. A deformed variety 

 of perch, with the back greatly elevated and the tail 

 distorted, has been noticed by Linnaeus as occurring 

 at Fahlun in Sweden, and in other lakes in the north 

 of Europe. Similar perch are also found in Llyn 

 Raithlyn in Merionethshire. A fish of this descrip- 

 tion is figured in the volume of Daniel's Rural Sports, 

 devoted to Fishing and Shooting, page 247. Speci- 

 mens of the perch, almost entirely white, have also 

 been found in the waters of particular soils." 



Perches can swim with great rapidity, and they 

 often associate together in considerable troops. In 

 fine tranquil weather these troops may be observed 

 in a lake, a river, or even a large ditch, drawn up in 

 lines with all the regularity of an army near the sur- 

 face of the water, and perfectly motionless. But 

 their perceptions are very keen ; for the least dis- 

 turbance of the state of things around, sets the whole 

 instantly off with wonderful celerity ; and even when 

 one who is observing them is aware of nothing cal- 

 culated to give alarm, they will dart off as if an elec- 

 tric shock were discharged into the whole. 



Perches are exceedingly voracious. Their com- 

 mon food consists of tadpoles, water-newts, frogs, 

 and other reptiles, and also of worms, molluscous 

 animals, and small fishes. It is alleged that they 

 sometimes pay rather dearly for their fish dinners, 

 for they sometimes swallow the stickleback, the 

 strongest spines of which fasten in the gullet, so that 

 the perch can neither get it up or down, and conse- 

 quently it is starved to death. The strong spines in 

 the dorsal tin of the perch sometimes make it a very 

 unpleasant mouthful for its still more ravenous neigh- 

 bour the pike ; and sometimes when the perch has 

 been actually seized, the pike may be seen to shake 

 it out again, apparently in great pain. There is one 

 enemy, however, against which the perch has no de- 

 prolirlc. This is a little feeble crustaceous animal of 

 _ the genus Ci/nn>t!i<; which enters the mouth of the 

 fish along with the water, and preys upon the sub- 

 stance of the gills. The gills of every fish are the 

 most susceptible parts of it ; and we need not won- 

 der that a perch, which has perhaps hundreds of these 

 little creatures eating away at its gills at the same 

 time, must suffer the greatest agony that can be in- 

 flicted on a fish. 



It is generally understood that perch are not fertile 

 till the third year. They spawn in April or May, 

 according to the season and climate, and they are 

 very prolific. The eggs are usually deposited among 

 aquatic plants, such as the sterns of reeds and rushes. 

 They are not buried in beds like the eggs of the 

 salmon, but united to each other in a species of little 

 strings. Bloch mentions three hundred thousand 

 eggs being found in a perch only half a pound weight, 

 and more than three times the number in one of a 

 pound weight. The perch is tenacious of life, and 

 may be carried in wet grass fora pretty long distance, 

 so that nothing is easier than to stock any suitable 

 water with perches. 



PERESKIA (Haworth). A genus of West 

 Indian fruit-bearing shrubs, commonly called the Bar- 

 badoes gooseberry. This genus wa's named Cactus 

 by Linnicus, and it is still kept in the order Opnnli- 

 acc<s or Cactccc. It differs from the other Cacti in 

 having more of a ramified and shrubby appearance, 

 as well as a hostile character, being profusely armed 



with spines. The fruit is about the size of a small 

 plum, and very pleasant to eat. They are perfectly 

 easy of increase by cuttings ; and they make an ex- 

 cellent stock on which to work the other Cacti, par- 

 ticularly the Cercus tntncahis, which, growing from 

 an elevated stem of a pereskia, is a beautiful ornament. 



PERGULARIA (Linnaeus). A genus of tropical 

 climbing shrubs, bearing curious pentandrous flowers, 

 and belonging to Asclcpiadcce. It is easily cultivated, 

 and the flowers are highly valued for their fragrance. 



PERIPLOC A (Linnaeus). A genus of deciduous 

 and evergreen climbing shrubs, belonging to the natu- 

 ral order Asclepiadcee. Three of the species are from 

 the south of Europe, and one is found in India. The 

 P. grcecci is a common bower plant in our gardens, 

 and, like the others, is propagated by layers. 



PERIPTERA (De Candolle). A curious flower- 

 ing evergreen shrub from New Spain, belonging to 

 MalvacecE. From the remarkable shape of the flowers 

 it is called the crimson shuttlecock. It succeeds in 

 our stoves, and is increased by cuttings rooted in the 

 usual way. 



PERIWINKLE is the Vinca minor of Linnasus, 

 which, with several other species, are frequent in our 

 flower borders ; and an Indian sort, V. rosca, is com- 

 mon in our hothouses. They belong to Apocyneee. 



PERLID^E (Leach). A family of neuropterous 

 insects, belonging to the tribe Filicornes, and distin- 

 guished by having three joints in the tarsi ; the man- 

 dibles small and membranous ; the posteriou wings 

 larger than the superior, and folded on the abdominal 

 margin when at rest ; the body is long, narrow, and 

 flattened, and the wings, when the insects are not in 

 the act of flying, are carried flatly upon the back ; 

 the abdomen is generally terminated by two filiform 

 threads. These insects frequent the neighbourhood 

 of water, and are very inactive ; they are especial 

 favourites with the trout, and imitations of some of 

 them are amongst the most "killing flies" in the fly- 

 fisher's entomology. The larva, as we have long- 

 been aware, is an active insect which resides in the 

 water without any cases, although the contrary is 

 expressly stated by Latreille. A figure of one of 

 these larva; has been published in the German period- 

 ical, Der Naturforscher, full half a century ago ; and 

 yet, from ignorance of this fact, and the assertion that 

 the larvae reside in cases like the caddice worms, the 

 greatest confusion has been made by those authors 

 who have attempted to arrange the Ncuroptcra in a 

 natural system. The type of the family is the Perla 

 bicaiidata, the specific name of which, however (two- 

 tailed), indicates a generic character. It is not very 

 common. There are other species of the genus, the 

 males of which have very short wings ; others, which 

 differ only in having wings of equal size in both sexes, 

 form the' genus Isogcnus of Newman. Ncmoura of 

 Latreille is generically distinguished by having no 

 filiform appendages at the extremity of the abdomen, 

 There are many species of this genus which depart 

 from the habit of the family by being generally found 

 in damp woods. Some other genera have been de- 

 scribed' by Mr. Stephens in his Illustrations of British 

 Entomology, together with descriptions of all the 

 species. 



PERSEA (Ggertner). A fruit tree called, in the 

 West Indies, the alligator-pear. It belongs to Lau- 

 rincB, and was formerly called Laurus pcnea. It is 

 propagated by layers. 



PERSICA (Tournefort). A genus of fruit trees 



