THE ANATOMY OF THE COLUMBZ. 229 
35. ON SOME POINTS IN THE ANATOMY OF THE 
COLUMBA* 
In the present communication it is not my intention to describe in 
detail the anatomy of any single kind of Pigeon, because that can be, 
most of it, learnt from the dissection of any common species: but, 
from the opportunities which are presented to me in the performance 
Page 249. 
of my prosectorial duties, it will be my endeavour to point out those 
peculiarities which I have been able to recognize in the soft parts of 
the large number of generic forms of the Columbe that have passed 
through my hands. It is my hope that those naturalists who have 
opportunities of examining genera and species which it has not been 
my good fortune to obtain, will recurd their observations, not omitting 
those points on which I shall endeavour to lay stress on the present 
occasion. 
_ That there is not a perfect constancy in the pterylosis and visceral 
anatomy of the Pigeons has been known for some time. WNitzsch, in 
his work on Pterylography, incidentally mentions that in the genus 
Goura there are no ceca to the intestine, and that the gall-bladder 
is absent. The same facts are noted by Hunter.t The former 
naturalist also refers to the absence of the oil-gland in the same 
genus. Prof. Owen says{ that the gall-bladder is constantly defi- 
cient—a statement which, as will be seen further on, requires some 
qualification. The fact that all the European species of Doves belong 
to the genera Columba, Turtur, and Pterocles has caused zoologists to 
estimate the characters of the whole suborder more from these than 
from the much larger number found in extra-European countries; 
and the results arrived at from a more extended study tend consider- 
ably to modify the prevailing impression as to the constancy of 
certain characters. 
The differences observable in the following structures have engaged 
my attention :-— 
1. The number of rectrices. 
2. The presence or absence of the oil-gland, which is never other- 
wise than nude. 
3. The presence or absence of cxca to the intestine, which in no 
* “Proceedings of the Zoological Society,” 1874, pp. 249-59. Read, May 5, 
1874. 
+ “ Essays and Observations,” vol. ii. p. 291. 
= “ Anatomy of Vertebrates,” vol. ii. p. 177. 
