50 IDENTIFICATION. 



shoulder blade. In the Swifts, kingfishers, and Hoopoe the femoral 

 tract extends from the extreme end of the ischium to the knee ; but in 

 the Bee- eaters it reaches neither the knee nor the pelvis. The 

 ventral tract is generally unbroken, but in the Cranes and Curlews it 

 has a long branch. In the Passerines, as shown by our Thrush, it is 

 a narrow strip with four branches. 



Probably few but cooks and poulterers know to what narrow spaces 

 a bird's feathers are confined ; and fewer still are aware that the 

 pattern of the tracts is an aid in identification. In Nitzsch's 

 " Plerylography" there are a number of maps of feather distribution, 

 to which those taking an interest in the subject should refer ; and in 

 the Central Hall of the Natural History Museum, at South 

 Kensington, will be found our typical Thrush, with a large number of 

 examples of bird structure and plumage — an admirable arrangement 

 which every one should visit, as they should also visit the Bird 

 Museum at Brighton, once Mr. Booth's and now the Corporation's, out 

 on the Dyke Road, a mile from the Jubilee Clock Tower. 



But are there no other means of identifying a bird? Yes ; by his 

 flight. But how can you classify flight ? It is as difficult as classifying 

 a man's gait, which is just as unmistakable once you know it. In our 

 notes we have endeavoured to give as good an idea of the flight as we 

 could, but we are conscious of the feebleness of our effort. And so 

 •with the syllabisations of the song. Attempts have been made to 

 reduce the song to musical form, but those who have tried over such 

 things even on the flute and piccolo and flageolet, know what a 

 burlesque is the result. The nearest approach to it is got by a series 

 of whistles, one for each bird, artificial syringes in fact, for a bird's 

 voice does not come from his larynx but from his syrinx lower down. 



Another means of identifying birds is by measurement. That we 

 have done our best to encourage by a table, which is the result of a 

 large number of observations and some two thousand calculations, 

 and which took more time than anything else in our little book. If 

 this is used in addition to the analyses and keys, there will be few 

 failures in identification. The eggs we have dealt with in a similar 

 manner, and we would have added the nests had we been able to 

 discover a workable system of sorting. There are several well- 

 defined types of nests. There is the Sand Martin's nest, for instance, 

 which is a burrow, such as is used by the Kingfisher and others ; there 

 is the Duck's nest made on the ground ; there is the floating nest such 

 as is made by the Grebe ; there is the mud nest such as is made by 

 the Thrush and the House Martin ; there is the nest in a tree trunk 

 bored by the Woodpeckers ; there is the flat nest of the Ring Dove, 

 and the Stork ; there is the cave nest of the Rock Dove : there are 

 the woven nests of so many of our small birds, the basket nests of 

 the Crows, the felted nests of the Dippers, the bottle nest of the 

 Tits, and the domed nests of so many other birds ; and then there 

 are, of course, the mere scratch nests of the Phasianidce, and the no 

 neits at all of the Terns ; and in addition to these are the adapted 

 neits of the Hobby and Peregrine, and the peculiar foundling 

 arrangements of the Cuckoo. 



And among these nests we can have another division into those that 

 are built only for the year, and those that are returned to again and 

 again, which are generally bulk by the birds that pair for life, like the 



