49 



Phryganea. 



The old English word *Cadas means a case for security. The word still lingers in 

 tea-caddy. The case-worm or larva of Phryganea is a soft-bodied creature, but it has a firm 

 head and strong jaws. It is supplied with six legs, well adapted for locomotion, and with 

 two hooks at the end of the tail by which it secures itself in its case. It is a rapacious 

 and pugnacious insect. It feeds upon fresh-water molluscs, larvae, polyps, etc. As a 

 builder it makes use of the materials at hand. The old Free Masons may have taken a 

 lesson from it, and Longfellow might have had it in mind when he sang, — 



" That is best which lieth nearest 

 Shape from that thy work of art." 



Sometimes the case is made of sticks, sometimes of grains of sand, and, in Great Britain, 

 sometimes of the shells of the small river-snail (Planorbis), even while their proper owners 

 have them in occupation. The cases not only serve for protection but for anchorage also, 

 and they are found to be heaviest where the current is strongest— the creature having 

 added materials to increase the weight. 



If the caddis be deprived of its case, it will at once set to work to construct another * 

 and, in confinement, it will build of materials supplied to it, such as small fragments of 

 glass and coral and the broken teeth of combs. However rough the outside of the case 

 may be, the inside is perfectly smooth, for it is lined with the same cement which binds 

 the materials together, and which is exuded from the mouth of the creature. 



It is interesting to watch the caddis shifting his ground, moving his habitation from 

 ene part of the river-bed to another. So much of the body as will allow the legs free 

 motion is protruded and the creature strains like a horse with a heavy load, whilst its 

 dwelling moves forward more or less steadily accordingly as it presents a smooth or 

 roughened surface. 



Before the pupa change takes place the caddis draws itself entirely into its snug 

 quarters, and spins a strong netted covering over the entrance of the case. Having thus 

 " barred the door " against intrusion, it dozes off into the long sleep, the waking from 

 which shall be an introduction to a new life, in another element. 



The Phryganidse in their perfect state differ from others of the Neuroptera, in that 

 they are covered with minute hairs. Hence Westwood and other English naturalists have 

 classed them as a separate order, the Trichoptera (Gr. 0pi£, hair ; itrepov, a wing) or hairy- 

 winged insects. 



In dress the Phryganidse are a sober people — browns, drabs and yellows are their 

 favourite colours. Gross-venations give their wings a netted appearance. Their antenna? 

 are long — in some instances very long, and the wings are carried longitudinally. The 

 females deposit their egg masses early in August on some surface projecting from the 

 flood. "Westwood tells us (Int. to Mod. Class, of Ins. Vol. II. page 62) that occasionally 

 they descend the stems of water-plants and lay them under water. The egg- mass resembles 

 miniature frog-spawn- It is an accumulation of drops of gluten containing embryons in 

 the form of minute green specks. The young larva? burst forth in September, and proceed 

 at once to construct their dwelling. They afterwards repeatedly " lengthen their cords 

 and strengthen their stakes " according to their requirements. 



" Our rivere abound with fish of various kinds, which at particular seasons derive 

 a principal part of their food from insects, as the numerous species of the salmon and carp 

 genus. These chiefly prey upon the various kinds of Trichoptera in their larva state called 

 ease or caddis-worms, and in their imago, May-flies." (Xirby and Spenee, Int. to Ent. 

 Letter IX.) 



The adult Salmon proper, Salmo solar, is believed by the best authorities, to eat little 

 or nothing during its sojourn in fresh water. It leaves the ocean fat and returns to it 

 emaciated. The above remark, therefore, does not apply to Salmo solar ; but it does apply 



*Kaddos, dim. of Kados, Gr. Parvus cadus, a small pot or jar, a ballot-box. See Schrevelii by 

 Eobertson, A. D. 1676, 



4 (EN.) 



