238 
sexual selection: birds. 
PabT* 
the upper exposed surface of the plumage has been th u ® 
coloured in both sexes, whilst the lower surface in y ' 11 
males alone has been variously ornamented throng' 1 
sexual selection. Finally, from the facts given in tl' eS ® 
four chapters, we may conclude that weapons for battle 
organs for producing sound, ornaments of many 
bright and conspicuous colours, have generally be^ 
acquired by the males through variation and ses«‘ l1 
selection, and have been transmitted in various n'». yS 
according to the several laws of inheritance— the i’ (; ' 
males and the young being left comparatively but l ^ 6 
modified." 
59 I am greatly indebted to the kindness of Mr. Selater for ha* 1 ®* 
looked over these four chapters on birds, and tho two following 
on mammals. By this means I have been saved from making 
about the names of the species, and from giving any facts which af 
actually known to this distinguished naturalist to be erroneous. 
of course lie is not at all answerable for tho accuracy of the statenV 11 5 
quoted by me from various authorities. 
