MONOGRAPH OF THE PETRELS. 



which in some species appears brighter during the breeding season, but as these parts 

 change colour in the dry skin, accurate information on these points can only be 

 obtained from living or freshly killed specimens. 



A marked peculiarity of these birds is the habit of ejecting a foetid fluid 

 from their nostrils, which is apparently used by certain species as a means of 

 defence, when it can be discharged to a distance of three feet at the approach of 

 any intruder. Owing to the introduction of the mongoose and other small 

 carnivorous mammals into their breeding haunts, some species, such as (Estrelata 

 jamaicensis and newelli, have already been completely exterminated, and others 

 appear to be in danger of extinction. The habit of some species of nesting in 

 immense colonies is also leading to similar results, as, for purposes of food, the eggs are 

 taken and young frequently robbed and killed in such countless thousands that 

 extermination becomes only a matter of time. 



In his preliminary remarks on the Order Tubinares in the twenty-fifth volume of the 

 " Catalogue of Birds," Salvin has reviewed the previous attempts to classify the Petrels, 

 quoting the characters propounded by Fiirbringer (1888), Seebohm (1890), Bowdler 

 Sharpe (1891), and Gadow (1892). Of the work of W. A. Forbes, he wrote as follows : — 



" The late William Alexander Forbes's Memoir entitled ' Report on the Anatomy 

 of the Petrels ' (Tubinares) collected during the voyage of H.M.S. ' Challenger ' (see 

 the Report of the Scientific Results, etc., Zoology, Vol. IV., Part XL, 1882), gives by 

 far the most complete account of the anatomy of this Order, discusses the relationship 

 of a large number of species representative of many genera, gives a good resume of 

 the literature of the subject, and the author's views as to the relationship of this 

 to other Orders of the Class Aves. 



" As the whole of the spirit-specimens possessed by me at the time were placed 

 at Forbes's disposal and were used in compiling his Memoir, I have little to say on this 

 branch of the subject beyond pointing out that I have ventured to depart to some 

 extent from Forbes's classification in the present ' Catalogue.' In doing so, I have 

 to a great extent returned to the older plan of keeping the Albatroses distinct from 

 the rest of the Petrels, and in restoring Forbes's Oceanitidce to the neighbourhood 

 of the genus Procellaria. That such an arrangement is more convenient can hardly 

 be doubted, and I think it can be justified. 



" Regarding the position of the Tubinares in the Systema Avium much difference 

 of opinion has existed, and the final disposition of the Order is hardly yet established. 

 Most authors placed it in juxtaposition to the Laridon,, but this allocation was objected 

 to by Garrod and Forbes, who asserted that the Steganopodes and Herodiones, as 

 understood by them, are its nearest allies, thus confirming the suggestions to that 

 effect advanced by 1'Herminier, Milne-Edwards, and Huxley." 



I am greatly indebted to Mr. W. P. Pycraft for the following chapter, which 

 contains some valuable and original observations. 



XIV 



