386 



Zoological Society : — 



having respect to the length of their hills, hut to the degree in which 

 they have retained a certain embryological simplicity of structure, 

 and are thus less typically ornithic than their relatives the Gulls, on 

 one hand, and the Ibises, on the other. 



The typical Fowls and the typical Geese and Ducks appear to 

 form two more groups of equal value with the Ralline and Pluvialine 

 groups ; but as these two simple types do not bear very directly upon 

 the subject of this present paper, they will be considered on some 

 other occasion. 



Any one who has mastered the development of a Rail or a Plover 

 will be in a state of fitness to study the meaning of what he will see 

 in the structure of the Heron and of the Crane. 



At present my view of the matter is, that, whilst the Heron has 

 risen considerably higher in the bird-scale than the Crane, yet they 

 are intimately related ; moreover, that the Heron has full two- 

 thirds of the ralline nature in it to one of the pluvialine, and, on 

 the other hand, that the Crane has in it twice as much of the 

 Plover as of the Rail. 



In supposing these birds to be thus double in their nature, I do 

 not forget that they have characters peculiar to themselves alone ; 

 identity-characters they might be called : we see this everywhere in 

 nature ; and those of us who have large families know well that, 

 whilst each child is in one sense a copy of both parents at once, yet 

 he holds his own, and has so much and such well-marked indivi- 

 dualism as to make him in a certain sense like the starting-point of 

 divergence towards a distinct species. I here append a sort of scheme, 

 showing some of the more important relationships of the Kagu, one 

 of the best examples of a multiple type : — 



Rallus. 



Ardea. 



Grus. 



Pluvialis. 



Crex. 



I 

 Brachypteryx 



Nycticorax. Anthropo'ides. Himantopus. 



Tigrisoma. Balearica. CEdicnemu* 



I I 



Rhinochetus. Eurypyga. Psophia. 



The Rhinochetus, the Psophia, and the Eurypyga are on the same 

 level ; they are intimately related inter se, and very closely also to the 

 Cranes and Herons. I am not aware whether, in placing them on 

 the same line, I have truly indicated the ornithic height of each. In 

 the upper line it is certainly not so ; yet that is a natural arrangement 

 in one important matter ; for the Heron comes near to the Railj^^and 

 the Crane to the Plover, and all are intimately related. 



The Psophia is the truest Crane in the bottom line, yet its skull 

 is principally ralline in character ; the Eurypyga comes nearest to the 

 Heron : as for the Kagu, whether it be most of a Crane, a Night- 



