Force of Hereditary Instinct. 209 



but are in the breeding places for six months or so. 

 Mr. Broinowski has this very suggestive passage in 

 one of his volumes : 



" The force of hereditary instinct is never more 

 strongly evidenced than when we find it asserting 

 itself in some immaterial trait that has no effect upon 

 the present, except as a mark of evolution, but clearly 

 points back to the discarded habits of earlier races. 

 Among the Centropi we found the parasitic custom 

 unknown ; each pair made their own dome-shaped 

 nest, and performed the task of rearing their young 

 like any other virtuous birds. The Eudynamis cut it- 

 self free from all domestic obligations, and left its 

 young to be tended by kindly crows ; thus proving 

 that there is a wide racial gap between the two 

 genera. The gap we may consider bridged over in 

 the chain of evolution by the Chrisococcyx ; for the 

 shining cuckoo, though a true parasite, is usually 

 found to deposit its egg in a dome-shaped nest having 

 a very small entrance. In New South Wales, the 

 Malurus cyaneus and the Geobasileus chrysorrhous are 

 forced to be foster-parents. Mr. Bennett, in writing 

 of the Lucidus, states that he has found the egg in the 

 nest oi Acanthea chrysorhicea, and that he has seen a 

 nest of this bird with five eggs, that of the cuckoo 

 being deposited in the centre of the group, so as to 

 ensure its receiving the warmth imparted by the 

 sitting bird, and thus less likely to be addled. He 

 also narrates the following incident : A white shafted 

 flycatcher {Rhipidura albiscapa) was shot at Ryde, 

 near Sydney, in the act of feeding a solitary young 

 bird in its nest, which, when examined, was found to 

 be the chick of the bronze cuckoo of the colonists." 



