776 EEPORT OF aOMMlSSIONER OF FISH AND FISHERIES. [6] 



fragments; five, minute insect larvae; four, Entomostraca, and eight, 

 small particles of vegetation. 



Only four lots were received from the spring, on the 9th, 14th, 17th, 

 and 25th of February, after which all died of starvation. In the first 

 hundred only one was found which had taken food, and this had eaten 

 a trace of filamentous Algse and a minute fragment of the parenchyma 

 of some higher plant, with a few diatoms. But one of the second hun- 

 dred contaiued even a trace of food, a minute quantity of some thread- 

 like Alga, the cells of which still contained a little chlorophyll. In the 

 third hundred likewise, food was found in but one. This consisted of 

 a few particles of vegetable parenchyma, doubtless derived from the 

 decaying plant structure in or around the water. In the third lot of 

 only forty-two specimens, six showed traces of food, consisting almost 

 entirely of a few filamentous Algse (including a fragment of Oscillatoria) 

 and a little vegetable parenchyma. Desmids and diatoms were observ- 

 ed in trivial numbers. 



The total number received from the spring was two hundred and forty- 

 two, of which but eight were found to have eaten anything (a little over 

 three per cent, of the whole), and these had taken only Algse and veg- 

 etable fragments. 



An example of the water of the spring sent me contained many Algse 

 but no animals larger than rotifers. The water of the hatchery, being 

 exposed in ponds of considerable size, afforded a better opportunity for 

 the development of animal life, to which fact was doubtless due the oc- 

 currence of insect larvae and Entomostraca in the intestines of the fishes 

 reared in it. The situation of the spring, on the other hand, was par- 

 ticularly unfavorable, as it was under the hatchery, and consequently 

 in the dark. 



The observations above described on the specimens kept in spring 

 water have but little value, for the reason that evidently very little food 

 was contained in the water flowing through their cage. The vegetation 

 in the streams being chiefly filamentous Algae and the number of Ento- 

 mostraca apparently trivial, very little of either vegetable or animal 

 food could reach the little prisoners. It is not surprising, therefore, 

 that, notwithstanding their greater age and the higher temperature of 

 the water in which they were kept, a much smaller ratio of the speci- 

 mens had taken food than of those captured in the hatchery. From the 

 contents of their intestines we can only infer that these fishes, reduced 

 to a desperate strait by starvation, will snatch at almost anything con- 

 tained in the water. The result obtained by a study of those from the 

 hatching-house was more significant, but still unsatisfactory. It seemed 

 to indicate that in confinement whitefish fry will feed upon both ani- 

 mal and vegetable structures to some extent, and that they can be in- 

 duced to take minute fragments of the higher crustaceans, but not in 

 sufficient quantity to keep them alive. The fact that animal food was 

 more abundant than vegetable in this last lot indicates nothing of their 



