276 T1LE HISTORY OF ANIMALS. [~B. IX. 



about and feeding them, and neither crowing, nor desiring 

 sexual intercourse. And some male birds have been seen to 

 be so effeminate from their birth, that they neither crowed, 

 nor desired sexual intercourse, and would submit themselves 

 to any males that desired them. 



3. Many birds at particular seasons change both their 

 colour and their voice, as the blackbird, \vhich becomes 

 russet instead of black, and assumes another voice, for it 

 sings in the summer time, but in winter it chatters and 

 screams violently. The thrush also alters its colour, for in 

 winter it is grey, and in summer is variegated on the neck ; 

 Jmt its voice does not alter. The nightingale sings unceas- 

 ingly for fifteen days and nights, when the mountains 

 become thick with leaves. As the summer advances it 

 utters another voice, not quick and varied, but simple ; its 

 colour also is altered, and in Italy it is called by another 

 name at this season of the year. It only shews itself for a 

 short time, for it lies concealed. 



3. The erithacus, and the bird called pho3nicurus, are 

 changed one into the other. The erithacus is a winter bird, 

 the pkoenicurus a summer bird ; they differ in nothing but 

 the colour. The sycalis and melancoryphus are the same, for 

 these also are interchanged. The sycalis is found in the 

 autumn, and the melancoryphus immediately after the end 

 of the autumn. They also differ from each other in nothing 

 but their colour and voice, and to prove that it is the same 

 bird, each kind has been seen immediately after the change 

 took place ; and when the change was not quite complete, 

 there was nothing characteristic of either form. Nor is it 

 absurd to suppose that these birds change their voices or 

 their colours, for the dove utters no sound in the winter, 

 unless it may be on a fine day in a severe winter, when it 

 will utter its sound to the astonishment of those that know 

 its habits ; and as soon as spring commences, it begins to 

 utter its voice : and, on the whole, birds make the greatest 

 number and variety of voices at the season of coition. 



4. The cuckoo also changes its colour, and its voice is not 

 distinct, when it is about to leave us. It goes away about 

 the time when the dog- star rises, it having been with us 

 from the commencement of spring to that time. The 

 cenanthe, as it is called, disappears when Sirius rises, and 



