1890.] 



Correspondence. 



217 



generalization based perhaps as much on some mere accident that has 

 strongly impressed the imagination, as on any serious consideration of 

 the facts observed. 



This practice of keeping a careful count has been in use for the last 

 few years among several ornithologists of my acquaintance, and it 

 would seem worth while to urge its general adoption among field natu- 

 ralists, if it were only to infuse a spirit of more scientific exactness 

 into their field-work. Our way is to jot down in the field with pencil 

 and paper — perhaps on the back of an old letter — every individual bird 

 seen or heard. If birds are few, and one's memory good, it may be 

 possible to do this all at the end of the day, but for most people, 

 and in the height of the season, the best way is to stop every little 

 while — in the inevitable pauses of waiting for some bird to show him- 

 self or to sing again — enter the species not already on the list, and 

 mark against each name the number seen or heard since the last entry. 

 Care must be taken to make due allowance for individuals already pre- 

 viously observed during the same day. in order not to unduly swell the 

 record by entering them over again. At the end of each day the results 

 can be transferred to the permanent record. To some the work may 

 seem an irksome slavery, hopelessly interfering with their enjoyment of 

 the beauties of nature. But with a very little practice they will be sur- 

 prised to see how easy it becomes, and how much more thoroughly they 

 observe when they have an increased incentive to identify every bird 

 and count the number in each flock. 



To illustrate the system, I give a brief extract from the notes taken 

 near Cambridge last season by Mr. Jonathan Dwight, Jr., and myself. 



