158 



der, simious, white appendages resembling spines, except that the ends 

 are knobbed. These are bent so as to point outward. The whole sur- 

 face of the egg is covered with minute short spines, these being longer 

 and more thicklj- placed within the ring. The natural color is dark 

 bronze-brown, but alcoholic specimens are of a dull white color, the 

 minute spines of brown showing distinctly on the surface. The eggs 

 are placed in clusters, the ringed end upward, resembling a cluster of 

 minute cups. — fF. M. Webster. 



PROFESSOR FORBES' INVESTIGATION ON THE FOOD OF FRESH-WATER 



FISHES. 



The number of insects which are known to feed on .fishes is very 

 limited, and these few could probably subsist on moUusks or other food, 

 and are thus not dependent on a fish diet. On the other hand, a large 

 proportion of fresh- water fishes depend more or less completely on in- 

 sects as food, and could, therefore, not exist without the insects. To 

 show the importance of insects as one of the principal food-articles of 

 fresh- water fishes has been the object of Prof. S. A. Forbes in a series 

 of admirable papers on the food of fresh-water fishes of Illinois. These 

 papers have been published under various titles in the Bulletin of the 

 Illinois State Laboratory of Natural History (Yols. I and II), between 

 the years 1877 and 1888. The wide scope of these investigations be- 

 comes at once apparent from the fact that no less than 1,22L fishes, be- 

 longing to 87 species of 03 genera and 25 families, and taken in various 

 months of the year from April to November, were carefully examined, 

 and the food contained in their stomachs determined and classi6ed. In 

 the concluding i^ortion of the series, which has just been published as 

 Article VIII of Volume II of the Bulletin, Professor Forbes presents 

 the summary of his researches and the generalizations derived there- 

 from. This summary concludes with a classified list of the objects de- 

 tected in the food of fishes, occupying 28 pages, and the list of insects 

 occupies nearly 13 pages. 



This list is of great interest to the entomplogist, not only from the 

 species it contains, but also from the many very common species which 

 are absent therefrom, and we regret that on account of its lengtli we 

 can not rej)roduce it here entire. We quote, however, Professor Forbes^ 

 equally interesting general remarks on the food of adult fishes so far as 

 they pertain to the insectivorous species: 



"It is from the class of insects that adult fishes derive the most im- 

 portant portion of their foo I, this class furnishing, for example, 40 per 

 cent, of the food of all the adults which I examined. 



''The prin(Mpal inse(;tivorous tishes are the smaller species, whose size 

 and food structures, when adult, unfit them for the ca[)ture of Ento- 

 mostraca, and y<t do not bring them within reach of fishes or Mollusca* 

 Some of these lishes have j)eculiar habits, which render them especially 

 dependent upon insect life, the little miuno v Phcnacobius^ for example. 



