Fifth Cubital Remex in the Carinatse. 79 



with its coverts, showing all normal relations ; in the Golden 

 Eagle (b, b') the coverts are present but no remex. The 

 former condition may be termed quincubital, the latter aquin- 

 cubital. Such is the constancy of one or the other condition 

 in each natural group, that I have as yet met with no excep- 

 tions anywhere, except among the so-called Picarise, many 

 of which are, and most of which probably will turn out to be, 

 quincubital. The Goatsuckers are a quincubital, while the 

 Swifts are quincubital*. Pterocles is aquincubital ; Goura is 

 aquincubital. Of course exceptions may turn up, seeing that 

 of the whole number of birds but a comparatively few have 

 as yet been tested for this point." 



Besides M. Gerbe and Wray, the only author who has as 

 yet touched upon this subject is Dr. Gadow, who, in his 

 recent paper " On the Numbers and on the Phylogenetic 

 Development of the Remiges of Birds/'' read before the Zoo- 

 logical Society in December 1888 (see P. Z. S. 1888, p. 655), 

 after alluding to the discovery of this phenomenon by the 

 authors above mentioned, adds to his tables of the numbers 

 of remiges in the bird's wing the condition of the fifth cubital 

 remex (whether present or absent) in the different groups, 

 so far as it was known to him. Simultaneously with 

 Dr. Gadow I had been making some researches on the same 

 subject, which were materially assisted by the preparation in 

 the laboratory of the Prosector in the Zoological Society's 

 Gardens of a certain number of birds' wings, arranged so as 

 to show the state of the fifth cubital remex very readily. It 

 is a pity, I think, that any knowledge on this curious point 

 once acquired should be lost, so that, although I cannot add 

 much to the subject, I propose to run through the various 

 orders of Carinate birds f, and to show in what cases yet 

 known to us the fifth cubital remex is present or absent, or 

 sometimes present and sometimes absent, and, in the case of 

 variable groups where it is desirable to be quite positive, 

 on what exact species the observations have been made. 



* [Some Swifts seem to be aquincubital. See below. — P. L. S.J 

 t As adopted in the arrangement given in my paper " On the present 

 State of tbe 'Systema Avium','' Ibis, 1880, p. 410. 



