194 



ON THE CHANGE OF 



%d, That in early life, the differences between 

 the male and female, are scarcely observable, but 

 that at a certain period the male assumes charac- 

 teristic distinctions, denominated by Mr Hunter, 

 " Secondary Properties," which the female then 

 wants. 



3d, That the female seldom makes an advance 

 towards these secondary properties, until her powers 

 of procreation are gone, when an inclination to re- 

 semble the masculine form takes place. Thus we 

 see that the males and females of animals in ge- 

 neral, and of birds in particular, closely resemble 

 each other for some time after their birth ; that to- 

 wards the middle or more vigorous period of their 

 lives, Nature gradually stamps upon the former cer- 

 tain external characters expressive of the sex to 

 which they belong ; and that after the chief pur- 

 poses of life have been fulfilled, the latter (females) 

 also converge into an imitation of those external 

 marks previously assumed by the males. The prin- 

 ciple, therefore, appears to me just as clear and well 

 established, as that death should ultimately resolve 

 each into the same elementary substances. 



One observation I have made upon old birds is, 

 that they die soon after they change the colour of 

 their feathers, and cease to lay eggs. 



I therefore repeat, that the change is never a mons- 

 trous occurrence, but always the natural result of age 

 and time. It would be idle, however, to cavil about 

 words, as it is my desire that this paper should 



