IIl8 BULLETIN OF THE BUREAU OF FISHERIES. 



the writing of such notes is not merely a record of what has been seen; it is in 

 itself a guide and a stimulus to further observation. 



Field records should be not only written, but, as far as possible, pictorial 

 also. Both sketches and photographs should be made. The technique of such 

 work is discussed in another place in this paper. One other point needs to 

 be insisted on here — that it is impossible to make notes in too great detail. 

 The experienced observer is apt to find his notes doubUng in volume with 

 each succeeding year, not only because he sees more, but because he learns the 

 wisdom of making full notes. He finds that his first year's notes leave him 

 in painful uncertainty about many points that he feels he should have made 

 clear. Thereafter, in succeeding years, he increases the detail of his note taking. 



Compilation of observations. — A connected account should be written 

 immediately upon completion of the field observations. The experienced 

 field observer will go into the field with a plan of observation in mind and 

 will proceed in accordance with this plan to work out first one part of his 

 plan and then another. It may seem that in the field one must take things 

 as they come and record events in the order of their occurrence, and indeed 

 it often is desirable to do this. Yet in the experience of the writer it is in 

 most cases better to proceed according to some plan, to analyze the problem 

 and to take up each part of it in turn. If the observer does this, he natu- 

 rally neglects for the time being those happenings that do not fall in that part 

 of the problem that he has immediately in hand. What he thus misses at 

 one time he must get at another. Not only are the best results obtained in 

 this way, but events often crowd so fast one upon another that there is no 

 other possible mode of procedure. 



If now the field observer proceeds in his work in accordance with a pre- 

 arranged plan, he will find it of great advantage to write a connected account 

 of his observations at the earliest possible moment. He should do this, if 

 possible, before the period of observation has expired. In this way he will 

 detect gaps in his plan and will be able to fill them in; he will perhaps find 

 the plan itself defective and be able to modify it before it is too late. If it 

 be here objected that the writer is laying down rules which ordinarily govern 

 the laboratory worker, and that these rules are not at all applicable in field 

 work, he can only reply that he has applied them in field work and always 

 with the result of obtaining better results in shorter time. 



TIMES AND PLACES OF OBSERVATION. 



Allusion has already been made to the fact that the breeding season offers 

 the best opportunities for the field observation of the habits of fishes. The fish 

 are then congregated at the breeding places, which are usually areas of shallow 

 water; their instincts often bind them strongly to a very restricted area; they 



