NATURE CALENDARS AND NOTE-BOOKSMAPS 51 



siderable amount of material will be obtained upon which it will be 

 possible to base some general statements. The entries will doubtless 

 be brief, especially if they are not confined to some particular class 

 of creature (see Part I, page 16, Bird Calendar). The note-book, 

 with its sketches and inserted photographs, will supplement the whole 

 calendar, or such parts as may most interest the particular observer. 

 One of the most useful combinations of calendar and note-book is 

 one which deals with the life histories of insects, such as have been 

 alluded to at the end of Chapter XXIII. The times at which various 

 changes of egg into caterpillar, caterpillar into chrysalis, chrysalis 

 into adult insect, form the basis of the calendar, while description of 

 methods of feeding, devices for protection, changes in appearance, 

 will go far to fill the nature note-book. 



SURVEY MAPS 



What the nature calendar does for time, the survey map will do 

 for distribution. Of course an original map should, if possible, be 

 made, but it would be something to record the occurrence of plants 

 and animals on an ordnance map,* or a copy of one. It is possible 

 to confine attention to particular forms, and one variety of the 

 survey map can have special reference to what is called a birds' nest 

 census. All the birds' nests in a certain district may be recorded on 

 the map, and a note-book kept with it, in which details of the suc- 

 cess or failure of the attempt on the part of the old birds to rear 

 their young may be set down. In addition to records of nests built 

 in the ordinary course, the results of putting up nesting boxes (see 

 figures 159 and 160),* for the purpose of attracting birds, may be 

 further added. (See also Part I., Introduction, page 5.) 



* See Appendix. 



