130 Romance of the Cuckoo. 



degree, and it is significant that the same ' feature exists, 

 or is in course of being developed among many other wholly, 

 or partially parasitic species such as the American Cowbirds 

 and Cuckoos.' Dr. Fulton, writing from New Zealand in Nature, 

 states ' that contrary to the usual opinion, there are numbers 

 of instances known where Cuckoos (species not stated) have 

 supervised the forced adoption of their offspring by other 

 species, have assisted in their feeding, and have reclaimed and 

 taken them away from their foster-parents.' 



Another feature in the economy of the Cuckoo is the 

 relatively small size of the sexual organs of the male, at the 

 Season of what should be their maximum development, and 

 this has been a source of not a little speculation, but this may 

 be connected with the preponderance of males resulting in a 

 loss of parental affection. 



There are other points in connection with our subject, 

 about which much speculation exists, but into which I will not 

 now enter, but merely refer to one other matter as it illustrates 

 ' Dimorphism,' and has reference to that curious phenomenon 

 which sometimes occurs in animals, where two varietal forms 

 exist side by side without such cause being in any way traceable 

 to local influences. 



As is well known to naturalists, the young Cuckoo differs 

 much from the adult, the plumage being a dark or ashy brown 

 colour, barred with rufous, giving it a beautifully mottled 

 appearance, with a white patch on the occiput, but there is 

 also another phase of plumage confined, it is believed, to young 

 birds only, the prevailing colour being rufous. Sometimes a 

 rich chestnut colour, similar to the plumage of a Kestrel, and 

 it is somewhat curious that this form is chiefly confined to the 

 female sex. 



Perhaps, in conclusion, I ought to refer to the assertion 

 made by some naturalists that the Cuckoo deposits its egg or 

 eggs only in the nests of those birds that laid similar eggs to 

 her own, but this is a statement much too sweeping in its 

 character. There can be no denying the fact that, in a general 

 sense, this may be true, but there are many remarkable excep- 

 tions, even in our own district, where the Cuckoo has deposited 

 its egg in the nests of the Ring Ouzel and Whinchat, but such 

 instances are rare, and in all probability, will be rarer in the 

 future, since I have little doubt that the eggs of the Cuckoo 

 have been and are undergoing a process of adaptation which 

 will ultimately result in fewer faultily-matched clutches such 

 as quoted above. Still it would be a difficult question to 

 answer why the Cuckoo should have laid their eggs in the nests 

 of Ring Ouzel and Whinchat in the height of the breeding 

 season when there could have been no difficulty in finding more 

 suitable nests, such as the Titlark and Skylark. 



Naturalist, 



