515 



recently taken food; but no other evidence of any abnormal condi- 

 tion was found. 



Other and smaller animals, not detected in July, also made their 

 appearance here as the season advanced. Water snails {Planorbis 

 and Lyinncca) were seen on the south side of the river in August, 

 and specimens were repeatedly taken on the north side from the 

 first of September on. October 28 a large crawfish was noticed, ap- 

 parently distressed however, and trying to leave the water. Large 

 numbers of Entonwstraca (Cyclops prasinus) were taken in the 

 stream October 13, although only a few dead nauplii had been col- 

 lected previous to that time. Female Cyclops bearing eggs were no- 

 ticed in shallow water in protected pockets along the north shore 

 after the September rise had scoured the river out. From November 

 I to 8, healthy Entomostraca, largely a species of Diaptomus, were 

 taken in considerable numbers both here and in the sanitary canal 

 at Lockport, and free living nauplii were common in the collections 

 from the sanitary canal. 



Winter Conditions, igi2. — Winter conditions in February and 

 March of 191 2, when the river at Morris was partly frozen, were 

 naturally in notable contrast to those of the midsummer season. The 

 river level was unusually low for the winter, ranging from six inches 

 to a foot above that of the preceding August. The water temper- 

 atures were, of course, near freezing. The mean of nine observa- 

 tions made February 16 was 33-8° F., and that of two observations 

 made March 19 was 34.7°. There was doubtless no less organic 

 matter in the water than before, and the sludge from the bar on the 

 north side had now a strong privy odor, as of undecayed human 

 feces, in place of the merely rank smell of the warmer weather. The 

 water itself had a sloppy odor, and was apparently carrying more 

 Carchcsium lachmanm than in midsummer. Decomposition being, 

 however, much slower at the winter temperatures, the oxygen content 

 of the water was relatively high, ranging, February 16, from 6.3 to 

 7.2 parts per million, equivalent to an average saturation percentage 

 of 48.76 for midstream samples. 



The Winter Search for Fishes. — ^Persistent efforts were made at 

 this time, under unusual difficulties, to learn whether fishes were to 

 be found at Morris under these winter conditions. The use of min- 

 now-seines, river-seines, and fyke-nets, was supplemented by re- 

 peated explosions of half-pound sticks of dynamite in different parts 

 of the river. To haul the seines it was necessary to cut out the 

 shore ice to a depth of one or two feet in order that the nets might 

 be landed. In this way a dozen hauls were made with a 150-foot 



