366 ORGANIC GROWTH sec. 



birds. That the peculiarly-constructed larynx of a singing- 

 bird must owe its peculiarities and capabilities entirely to 

 acquirement and inheritance, scarcely any one can doubt. In 

 these animals the faculty of singing is actually hereditary : it 

 is a fact that song-birds kept in captivity, even when they 

 have had no opportunity of imitating old birds, begin to sing, 

 and learn, though but imperfectly, to sing like their ancestors. 

 We may therefore expect that speech in animals, when it is 

 very simple, when it consists of only a limited number of 

 sounds and sound-combinations, will be inherited more com- 

 pletely than in ourselves. Hitherto so little attention has 

 been paid to these matters that even at the present day some 

 zoologists and zoological text- books still regard not only 

 reason but articulate speech also as exclusive possessions of 

 the human race. What knowledge have we of the speech of 

 animals to justify us in maintaining such a general distinc- 

 tion ? It is certain that the language of many birds possesses 

 a copious vocabulary, and among these are some of compara- 

 tively little intelligence, for instance, our domestic fowls. These 

 creatures converse with one another with their hoarse voices 

 often for hours together, as do also, among others, the 

 swallows by their twitterings. Although these conversations 

 are to us unintelligible, it is not extremely difficult gradually 

 to learn something of the language of fowls and other birds, 

 to understand their expressions of surprise and alarm, of 

 pleasure, invitation, and warning. After much careful study 

 it seems to me that such modes of expression are universal 

 among fowls, and that they are hereditary, for one finds them 

 used in the same way by individuals from the most various 

 districts, and even when chickens are taken from the fowl- 

 house when quite young they develop the same language. 

 In this case it is the same as in that of instinct : the simpler 

 the language, the fewer the definite requirements which the 

 powers of vocal expression have to satisfy, so much the more 



