FOREST, FISH AND GAME COMMISSION. 505 



nection. Dr. Needham, in dissecting a female sub-imago of this species, counted a 

 portion of the eggs in her ovaries, and on this basis estimated their entire number 

 at 1,340. 



The young, or nymphs, as they are termed, Hve under water. They may be recog- 

 nized by a study of the two forms represented at figures i, 2, 5 and 6 on plate 2. 

 It will be seen that they are slim, six-legged crawlers, bearing slender, barbed, 

 anal filaments, and with a row of tracheal gills or breathing organs along the outer 

 margin of the abdomen. Once seen they are easily identified. It has been truly 

 observed of these creatures by Dr. Needham, that the struggle for existence falls 

 upon them, and, consequently, there are several highly specialized groups, each nicely 

 adapted to its peculiar habits. Some of these nymphs live in or among the water 

 plants, while others burrow in the mud and obtain their food at or near the bottom 

 of the water. All of them are delicate morsels for fish, and are fed upon to a consid- 

 erable extent. 



The studies of Prof. Forbes have shown that Alay-fly larvje were eaten by 213 

 specimens representing 48 species, not counting the young. The larvae of Hexa- 

 geiiia, one of the commonest of the " river flies " in Illinois, were by far the most 

 important insects of this group, they alone amounting to about one-half of all the 

 neuropteroid larvae eaten. They made nearly one-half of the food of the shovel fish, 

 more than one-tenth of that of the sunfishes, and were the principal food resource of 

 half-grown sheepshead. They were rarely taken by the sucker family and comprised 

 only five per cent of the food of the catfish group. 



The abundance of these forms is well-knoAvn to almost anyone who is at all 

 familiar with aquatic life. At times they occur in almost innumerable swarms. Such 

 flights have been compared to snowstorms, and Mr. Cheney, our late State Fish Cul- 

 turist, records an instance of having seen them cover the front of a large hotel, 

 windows, doors and every inch of woodwork, as though the house had been plastered 

 with them. This condition is not infrequent in Buffalo and vicinity. Only last 

 spring the writer observed in the lower section of the city that buildings were nearly 

 covered in the early evening by these insects, and they were so numerous as to be a 

 source of positive annoyance to pedestrians. Five, six or even twenty might alight 

 on a person at one time. Residents along the St. Lawrence river are familiar with 

 the immense annual swarms of these insects. A further idea of their abundance in 

 nature may be gained from the following observations by Dr. Needham at Saranac 

 Inn. In a quantitative study of a plat of 15 square feet, embracing the margin and 

 a portion of the bed of a small stream, he found 15 nymphs, or one to every square 

 foot of surface. 



