132 THE NATURAL HISTORY 



among whom, in their younger days, the sexes differ but 

 little : but, as they advance to maturity, horns and 

 shaggy manes, beards and brawny necks, etc., etc., strongly 

 discriminate the male from the female. We may instance 

 still farther in our own species, where a beard and 

 stronger features are usually characteristic of the male 

 sex : but this sexual diversity does not take place in 

 earlier life ; for a beautiful youth shall be so like a 

 beautiful girl that the difference shall not be discernible r 



" Quern si puellarum insereres choro, 

 Mir^ sagaces falleret hospites 

 Discrimen obscurum, solutis 

 Crinibus, ambiguoque vultu." — Horace. 



LETTER Vn 



RiNGMER, NEAR LeWES, Oct. 8, 1770. 



Dear Sir, 

 I am glad to hear that Kuckalm is to furnish you with 

 the birds of Jamaica ; a sight of the hirundines of that 

 hot and distant island would be great entertainment to 

 me. 



The Anni of Scopoli are now in my possession ; and I 

 have read the Annus Primus with satisfaction : for though 

 some parts of this work are exceptionable, and he may 

 advance some mistaken observations ; yet the ornithology 

 of so distant a country as Carniola is very curious. Men 

 that undertake only one district are much more likely 

 to advance natural knowledge than those that grasp at 

 more than they can possibly be acquainted with : every 

 kingdom, every province, should have its own mono- 

 grapher. 



