426 



NATURE 



[July 31, 1919 



Behaviour of a Cuckoo. 



A PAIR of pied wagtails built their nest beneath the 

 crest-tile at the end o^ the roof of a cowhouse. The 

 entrances to the nest were two, one at the gable end 

 where the mortar was loose, the other on the roof 

 itself beneath the tile. On June 24, at 5.30 p.m. 

 (G.M.T.), a female cuckoo circled round the building, 

 and presently, settling beneath the crest-tile, attempted 

 to ehect an entrance through the larger opening. But 

 the opening was too narrow, and the bird could not 

 force its body in beyond the shoulders. It therefore 

 flew away and settled upon an adjoining building, but, 

 returning in less than a minute, made a further attempt 

 and failed again. These efforts were repeated a 

 number of times without success. Two attempts were 

 then made through the smaller opening on the' .roof, 

 which, of course, also failed, and so the bird returned 

 to the main opening and made still further and more 

 determined efforts to enter, and the impulse to attain 

 its end seemed to be increasing gradually in strength. 



At 6 p.m. the bird betrayed symptoms of distress ; 

 its bill was often widely opened, and its efforts were 

 more frequent and more prolonged. At 6.10 p.m. a 

 final attempt was made ; turning upon its side, it tried 

 to force or scratch its way through the aperture, as 

 a terrier forces its way down a rabbit-hole, but still 

 it could not enter beyond its shoulders. K strange 

 tiling then happened. In addition to its muscular efforts 

 there were distinct signs of emotional manifestation ; 

 its wings were spread and waved and its tail was 

 outspread, and at the height of this manifestation .the 

 egg was protruded through the vent and fell to the 

 ground. All excitement forthwith vanished, and the 

 bird flew away and did not return. The emotional 

 manifestation, similar to that which occurs so fre- 

 quently* in bird-life during sexual emotion, evidently 

 coincided with the violent contractions of the cloacal 

 walls. 



There is a deal of evidence to show that the cuckoo 

 sometimes lays its egg upon the. ground, and then 

 picks it up in its bill and deposits it in the nest, and 

 sometimes actually lays it in the nest. Here we have 

 a case in which, one would think, the former method 

 would have been employed ; yet there was no 

 mistaking the fact that the activities of the bird 

 were dominated by a single impulse, the impulse 

 to enter the nest. Do some cuckoos employ 

 one method and some the other; and is there 

 a relationship, determined by racial preparation, 

 between the mode of behaviour and the type of nest 

 selected? If these questions can be answered in the 

 affirmative, must this particular cuckoo be regarded 

 as a prospective failure in the inevitable struggle for 

 existence? H. Eliot Howard. 



Hartlebury, June 26. 



Sparganophilus : A British Oligochset. 



Benham created the genus Sparganophilus in 1892, 

 and gave *a description of a new worm found at 

 Goring-on-Thames, 'under the title 5. tamesis. Since 

 that time other species have been added to the genus, 

 but no one has been able to confirm, extend, or con- 

 fute Benham 's statement that it was "a new English 

 genus of aquatic Oligochaeta " {Q.J. Micr. ScL, 

 N.S., 34, 1892-93, p. iss)-. ^ ^ ^ , , ' , 



Looking over my collections to-day, I have had the 

 good fortune to find some well-preserved specimens 

 of Sparganophilus collected in Cornwall in April, 1910. 

 I noted the worm at the time, and recorded it provi- 

 sionally as Helodrilus elongatus, n.sp. Until now it 

 has been hidden away and forgotten. 



The Cornish species differs from that found in the 

 Thames in several ways, and resembles somewhat 

 closely S. eiseni, Smith, found in America, and 

 NO. 2596, VOL. 103] 



S. benhami, Eisen, from Mexico. At present I loolc 

 upon it as a new species, and propose to retain the 

 trivial name already applied to it, and describe it as- 

 S. elongatus. It is nearly twice as long as 5. tamesis, 

 has from 200 to 250 segments, and is destitute of a 

 pygidium. The anus is not dorsal, but agrees in. 

 position with that of the earthworm. The girdle also- 

 is longer, extending over segments 15-27, but I have 

 only once been able to find any traces of tubercula 

 pubertatis. Hilderic Friend. 



"Cathay," Solihull, July 9. 



The Brent Valley Bird Sanctuary. 



The Brent Valley bird sanctuary of the Selborne 

 Society has been carried on for sixteen years, and,, 

 apart from the experimental work which has resulted 

 in the sending of nesting-boxes all over the country 

 and to different parts of the world, much pleasure has- 

 been given to very numerous visitors of all classes. 

 The committee has, until recently, been able to keep 

 things going on the profits obtained from the sale of 

 nesting-boxes, together with occasional donations. 



The war upset all arrangements, and turned the 

 balance in hand in 1914 into one due to the secretary, 

 so that it has been found necessary to make an appeal 

 for direct contributions. These may be sent to me at 

 "The Hermitage," Hanvv-ell, W.7, together with orders 

 for nesting-boxes. 



With a greatlv increased amount of land under 

 cultivation, and in view of the Government's afforesta- 

 tion scheme, the need for augmenting the number of 

 insect-eating birds is manifest, and the importance of 

 bird sanctuaries greater than ever. 



In these circumstances it may not be out of place 

 to express the hope that someone may come forward 

 and put the Brent Vallev bird sanctuary upon a per- 

 manent basis. Wilfred Mark Webb. 



Chairman. 



83 Avenue Chambers, W.C.i. 



THE 



STRUCTURE OF THE SOLAR 

 ATMOSPHERE. 



SOME of the extraordinary revelations of the 

 spectroheliograph, in its application to the 

 structure of the solar atmosphere, may be gathered 

 from the accompanying photographs, which have 

 been courteously placed at our disposal by Prof. 

 G. E. Hale, director of the Solar Observatory at 

 Mount Wilson, California. 



As is now well known, the spectroheliograph 

 yields monochromatic images of the sun in light 

 of any desired wave-length, and shows the dis- 

 tribution of the clouds of hydrogen, calcium, or 

 other vapours, which are not apparent in direct 

 observations by the integrated light. Further, by 

 a suitable adjustment of the second, or isolating, 

 slit of the instrument, different portions of the 

 same spectral line may be separately transmitted 

 to the sensitive plate, and the structure of the 

 solar atmosphere at different levels above the 

 photosphere may thus be investigated. In recent 

 years the red line of hydrogen, Ho, has been 

 largely utilised, and the photographs obtained 

 with the central portion of this line are believed 

 to represent the highest levels at present attain- 

 able. The work at Mount Wilson has been carried 

 on for several years with a spectroheliograph of 

 5 ft. focal length, but during the last few years 



