4 JACOB REIGHARD. 



sharp contrast with the surrounding silt-covered bottom. The 

 patches show where the suckers have been breeding. 



The water of a rapid is rarely so smooth that one can see 

 readily into it. Not often is such a rapid near a bridge or 

 other perch; but under this Mill Creek bridge the surface of the 

 stream is but little broken and on a sunny, cloudless day, when 

 the water is clear and there is no wind to ruffle iits surface, it is 

 possible to see in detail what happens on the rapid. With field 

 glasses the fish may be studied almost as readily as though they 

 w r ere in air. From this vantage point I watched the white 

 suckers at intervals. 1 



My work was done by day. It is well known that in the spring 

 suckers ascend small streams in great numbers at night and it is 

 possible that their breeding activities are continued at night. 

 They are often interrupted by colder weather or roily water. 



2. General Activities of Breeding Fish. About 2 o'clock on 

 April 23, 1903, I cautiously took my place on the Mill Creek 

 railroad bridge. Numerous white suckers were on the rapids. 

 Although I walked with extreme slowness and made no sudden 

 movements of any part of my body the fish were at once aware 

 of my coming and scurried to the shelter of the banks and nearer 

 pools. I sat quiet and in the course of fifteen minutes they began 

 to reappear in the shallow, swift water. Thereafter, for an 

 hour, any quick movement on my part resulted in the fish 

 starting swiftly up stream, but if the movement was not repeated 

 they dropped slowly down-stream to where they had been. 

 To get the field glasses to the eyes or the hand to the notebook 

 without startling the fish needed a movement so slow that it 

 must have been scarcely perceptible at the distance of twenty- 

 five or thirty feet at which the fish were. It was probably about 

 two inches per second. As time went on the fish became grad- 

 ually used to my presence and after an hour were no longer dis- 

 turbed by slow movements. By three o'clock twenty suckers 

 from eight to twelve inches long were on the rapid and were 

 moving slowly up stream in small groups. The fish stopped 



1 From April 23 to May 6, 1903. In Honey Creek near Ann Arbor, I saw them 

 breeding April 27 to May 2, and in Mallet Creek, Ann Arbor, on May 10, 1909. 

 The two creeks last named are only about a third the width of Mill Creek (Grand 

 Rapids) at the point at which the suckers were seen. 



