332 DR. GADOW ON THE ANATOMY OF PTEROCLES. [Mar. 21, 
large group and the Fowls the other, because then this Plover- 
Pigeon group would include a form, viz. Pterocles, which we know 
to be more closely allied to the Rasores than to Charadrius. It 
must also be remembered that Snipes and Gulls are closely related 
to the Plovers ; and of course Péerocles cannot be placed in such a 
position as would indicate that it is more closely related to the 
Gulls than to the Grouse. Thus it will be best to make a group or 
family Pterocletes, as Mr. Sclater has done, coordinate with those of 
Pigeons, Plovers, Gull, Fowls, and the like. 
On the other hand, if we are to answer the straightforward question 
Is Pterocles more nearly allied through its ancestors to the Pigeons 
or to the Fowls? we are compelled to say that they are nearest to the 
Pigeons. Of course they have many features in common with the 
Fowls ; but in no case we can include them under the latter, for the 
following reasons :— 
Pterocles shows some, although only a few, anatomical points 
which we only find amongst the Columbide, whilst all the other 
numerous points in which it resembles the Fowls are such as must 
have been common to the old ancestral Stork, as we find them again 
in some of the Limicole. But some of its Columbine features it is 
impossible to trace so far back, as they indicate a very high degree 
of specialization. Pterocles must have branched off from those 
birds which we may term “ incipient Pigeons,’ and then, for reasons 
we can only suggest (perhaps similar conditions of life, and the like), 
have preserved and developed many of those old characters which 
the Fowls have also inherited from the same source, and have them 
developed in a similar way, as living under the same conditions. 
The main part of the ancestral or incipient Pigeons at the same 
time started in another direction, losing, as they proceeded, many 
of the old characters’, and acquiring numerous new ones, till they 
became that highly specialized group which is now called Columbee. 
1 Among the most important characters common to the ancestral stock 
which the Pigeons have lost, or are in process of losing, are the following :— 
1. The Pigeons have nearly completely lost the cxcal appendages of the 
rectum, 
2. There seems to be a tendency to lose the ambiens muscle, as in many of 
the Pigeons it is completely absent, and in others this muscle is unstable in its 
presence. 
3. They have lost the aftershaft to the feathers. 
4, They have almost completely lost their nestling plumage, and the old 
character of being autophagous birds, as"their young are now hatched nearly 
nude, blind, utterly helpless, and depending entirely on their parents, and have 
to spend a considerable part of their childhood in a very imperfect state. 
