128 RAMBLES ABOUT HOME. 



Taking a careful survey of the whole thirty- two nests, 

 they suggested at once an ordinary village : there were, 

 for instance, handsome structures, and then again very 

 modest ones ; and while, perhaps, strictly speaking, the 

 causes that produce this variation in the dwelling-places 

 of birds are not the same as those which lead to a similar 

 state of affairs among mankind, yet in a remote degree 

 they are believed to be in many respects analogous. 

 For instance, there are industrious birds and lazy ones ; 

 plucky birds that are not daunted by obstacles, and de- 

 spondent ones that are cast down by shadows ; and this 

 of itself will account for a great deal of the variation in 

 birds' nests. That birds differ greatly in their tempera- 

 ments can hardly be doubted, and, if this be admitted, 

 may we not go a step further and claim also differences 

 in mental capacity, or, in plain language, may we not 

 say that the " smarter " the bird the better the nest ? 



Why these nests of the robin vary, simply is a mud- 

 lined nest being that which formerly, if not at present, 

 was best suited to the bird's welfare that a bird reared 

 in a poorly constructed and partially lined nest may 

 prove to be of greater ability and more energetic than its 

 parents, and this, joined with the fact that the bird's 

 mate may have been reared in a nest of perfect construc- 

 tion, of itself, would tend to remedy in part the defects in 

 construction that its partner might allow ; the facts to- 

 gether would certainly secure an approach to, if not the 

 complete attainment of, a typical robin's nest. So, as the 

 years roll by, the nest of the robin would remain substan- 

 tially the same ; but what slight variations circumstances 

 have caused to be made, if not detrimental, would also 

 be continued, and, if any marked changes of environment 

 occurred, increased. 



Why, indeed, a robin should line its nest with mud, 



