NATURE 



[March 6, 19 19 



The Supposed "Fascination" of Birds. 



It is well known that the stoat {Futorius ermineus) 

 sometimes? performs extravagant antics by way of 

 ruse in approaching rabbits or small birds, 'which, in 

 the opinion of some persons, are "fascinated" or 

 hypnotised by the display. 1 incline to believe that 

 fhe subjecj; of these manoeuvres becomes so deeply 

 interested, amused, or puzzled by the movements of 

 the acrobat that it defers flight until too late. This 

 view has been strengthened by what I witnessed 

 from my library window in the spring of 19 17. A male 

 blackbird was sitting on the open lawn ; a stoat was 

 racing round the bird at high speed, now rolling itself 

 into a ball, racing again, then leaping fully 2 ft. 

 high and turning an aerial somersault, and again 

 racing in circles. How long the performance had 

 been going on before I happened to become a specta- 

 tor I know not, but it went on under my eyes for 

 perhaps seven minutes, during which time the black- 

 bird never stirred and the stoat continued in violent 

 movement. Every moment I expected that it would 

 spring upon the bird, which it might easily have 

 done, but nothing of the kind happened. Suddenly, 

 in the middle of the performance, the blackbird flew 

 away; and the stoat, apparently not caring to ex- 

 hibit without a "gallery," resumed its normal gait 

 and disappeared in the bushes. 



Now if the blackbird was " fascinated " in the sense 

 of an arrest of motor volition, what broke the spell? 

 The acrobat was at the height of its antics when the 

 bird flew off'. One may assume, I think, that the 

 latter's interest in the performance was absorbing up 

 to a certain point, for it is contrary to the habits of a 

 blackbird to sit motionless for many minutes on a 

 spring morning; but it does not seem' as if its volition 

 had been affected. 



In his great w^ork on British mammals Mr. J. G. 

 Millais describes instances of the stoat (than which 

 there is no more bloodthirsty animal) resorting to 

 these acrobatic feats with no deadly purpose, finish- 

 ing up by romping with its audience of young rabbits 

 and worrying them in make-believe. In the case I 

 have described it does not appear that the stoat had 

 any intention of making its breakfast off the black- 

 bird. ■ Herbert Maxwell. 



Monreith, Whauphill, Wigtownshire, N.B. 



Girvanella and the Foraminifera. 



Bulletin No. 104 of the United States National 

 Museum contains the first part of Mr. J. A. Cush- 

 man's "Foraminifera of the Atlantic Ocean." 

 Workers in this group will find it of much value to 

 have a complete and well-illustrated account of the 

 foraminifera as occurring in the Atlantic. In this 

 paper there is, however, one doubtful point in regard 

 to affinity in which two distinct organisms are con- 

 fused, and this, if not corrected, will mislead the 

 student. I refer to the relegation of Brady's Hyper- 

 ammina vagans to the genus Girvanella, Nicholson 

 and Etheridge. It is a generally accepted opinion that 

 Girvanella is probably related to the blue-green algae 

 (Cyanophyceae), as shown by Rothpletz, Wethered, 

 Seward, Garwood, and the writer. In the earliest 

 descriptions Nicholson and Etheridge, it is true, held 

 Girvanella to be of foraminiferal affinities, and 13radv 

 compared it to H. vagans, but the consensus of 

 opinion is now in favour of its plant origin. As I 

 have elsevk^here shown (Aust. Assoc. Adv. Sci., 

 Adelaide, 1907), its larger dimensions, arenaceous 

 shell-wall^ bulbous • primordial chamber, simple, not 

 branching, tube, and absence of septation separate it 

 from Girvanella. In following Rhumbler (1913), 



NO. 2575, VOL. 103] 



Cushman includes other species of thread-like 

 rambling and attached organisms. Whether they 

 are all foraminiferal or algal in affinities can be 

 determined only by careful examination by means of 

 microscope sections, at the same time bearing in 

 mind that the structure of the true Girvanella tube is 

 not a mosaic of particles held by cement, but a finely 

 granula,r structure such as is seen in other living; 

 calcareous algae. The point here raised is directed 

 against the placing of the genus Girvanella, as defined 

 by Nicholson and Etheridge, with the Foraminifera. 



Fredk. Chapman. 

 National Museum, Melbourne, 

 December 23, 1918. 



Feeding Habits of Nestling Bee-eaters. 



The paragraph in Nature of March 28, 1918, p. 70, 

 upon a paper in which Mr. W. Rowan describes the 

 defaecation of the nestlings of the British kingfisher, 

 leads me to mention the habits of a bird also nesting, 

 in tunnels. I refer to the bee-eater (Merops). Mr- 

 J. E. Ward, recently a fellow-passenger from New 

 Guinea, told me that the young of a Papuan species 

 defaecate outside the nest but within the tunnel. The 

 faeces attract flies, which breed in the mass, and the 

 resulting larvae form the food of the very young 

 nestlings. As the flies later emerge, the young birds 

 have grown sufficiently to be able to catch the insects 

 on the wing. 



Mr. Ward noticed that nestlings in captivity did not 

 gape for food as do most young birds, and he was 

 thus led to investigate the' subject, with the result 

 above mentioned. Edgar R. Waite. 



S.A. Museum, Adelaide, September 6, 1918. 



THE COMMERCIAL USE OF AIRSHIPS. 



THE future of the rigid airship from the com- 

 mercial point of view is brought promin- 

 ently into notice by a paper lately issued by the 

 Air Ministry entitled "Notes on Airships for Com- 

 mercial Purposes." This memorandum discusses, 

 at length the possibility of the use of airships in- 

 the immediate future, and enters into a detailed 

 comparison between the large aeroplane and the 

 rigid airship. At the outset it is stated, however, 

 that the two types of aircraft, as at present de- 

 veloped, are not likely to compete with one another 

 seriously, since their characteristics are widely 

 different, the aeroplane being essentially a high- 

 speed, short-distance machine, while the rigid air- 

 ship is a long-distance, weight-carrying craft. 

 The great endurance of the airship and its power 

 of remaining in the air during a temporary break- 

 down of the machinery are valuable assets when 

 long flights over sea or mountainous country are 

 contemplated. The safety and comfort of pas- 

 sengers are considered to be greater in the case 

 of the airship than in that of the aeroplane. Irt: 

 connection with the possibility of loss by fire in the 

 former case the Air Ministry points out that there 

 has been only one such loss since 1914, despite the 

 fact that about 2^ million miles have been covered, 

 and that in this one case the cause of fire has 

 been ascertained and eliminated. It is conceded 

 that at present the airship is more affected by 

 bad weather than the aeroplane, but it is stated 



