18/4.] MR. GARROD ON THE ANATOMY OF THE COLUMB^E. 249 



1. On some Points in the Anatomy of the Columbce. By 

 A. H. Garrod, B.A v Fellow of St. John's College, Cam- 

 bridge; Prosector to the Society. 



[Eeceived March 19, 1874.] 



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 per- 

 formance 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 Colnmbse that 

 have passed through my hands. It is my hope that those natu- 

 ralists who have opportunities of examining genera and species 

 which it has not been my good fortune to obtain, will record 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. Nitzsch, in 

 his work on Pterylography, incidentally mentions that in the genus 

 Goura there are no caeca to the intestine, and that the gall-bladder 

 is absent. The same facts are noted by Hunter*. The former 

 naturalist also refers to the absence of the oil-gland in the same 

 genus. Prof. Owen saysf 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 Oolumba, 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-Euro- 

 pean countries ; and the results arrived at from a more extended 

 study tend considerably 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 caeca to the intestine, which in no 

 genera, except in Pterocles and Syrrhaptes, exceed half an inch in 

 length. 



4. The presence or absence of the ambiens muscle, which does 

 not seem as yet to have engaged the attention of naturalists, so far 

 as this suborder of birds is concerned. 



I. The number of tail-feathers in the (liferent genera of the 



Columbse. 



Nitzsch divides the Pigeons into those with 12 and those with 



* Essays and Observations, vol. ii. p. 291. 

 t Anatomy of Vertebrates, vol. ii. p. 177. 



Proc. Zool. Soc— 1874, No. XVII. \7 



