COMMISSION OF ERROE. 507 



as well as upon * dummies ' inert, inanimate substances, 

 such as stones or imitation eggs. 



Hancock tells us that birds ' do not discriminate nicely 

 the colours or other characters of their eggs ' a circum- 

 stance that points to deficient power of observation or 

 attention in this direction. Hence probably it is that we 

 hear of hens sitting on and hatching the eggs of other birds, 

 not noticing the difference until the young come forth. But 

 they also sit on, though they cannot hatch from, bodies that 

 bear but a faint resemblance to their own eggs, or to eggs 

 at all. 



Thus we are told of a cochin-china fowl sitting for some 

 length of time on two empty physic bottles, and at last 

 requiring forcible removal l a marked instance of error or 

 perversion of the maternal instinct. If the male bird of 

 paradise is killed, * the female will continue to sit upon her 

 eggs until she is starved to death ' (Lawson). Hens may 

 easily be made to sit on ' dummies.' Eomanes mentions a 

 Spanish hen of his that did so for three days, ' after which 

 time her patience became exhausted.' He also speaks of 

 a Brahma hen, that had hatched pea-fowl eggs, as deserting 

 'her family at the time when it is natural for ordinary hens 

 to do so, and in consequence all the pea- chickens miserably 

 perished.' 



He refers to a pea-hen that ' sat very steadily on addled 

 eggs for a period of four months, and had then to be forced 

 off in order to save her life.' And he illustrates ' in what a 

 high degree hereditary instinct may be modified by peculiar 

 individual experiences,' by the case of an old Brahma hen 

 that ' for the enormous period of eighteen months remained 

 with her ever-growing chicken,' a foster pea-fowl placed 

 experimentally under her in the egg state ; ' and throughout 

 the whole of that time she continued to pay it unremitting 

 attention. ... So long as they remained together the 

 abnormal degree of pride which the mother showed in her 

 wonderful chicken was most ludicrous.' 



A common result of premature hatching is the death of 



1 < Perthshire Constitutional,' November 9, 1874. 



