44 SUMMARY OF CURRENT RESEARCHES RELATING TO 



some instances the adaptations of the intestinal canal to the <liet, and 

 certain features of the ontogenetic development of some of the organs 



are brought to light. 



Iridescence of Pigeon's Neck.* R. M. Strong has made a careful 

 analysis of the metallic colours or iridescence of the sides of the neck 

 of the grey domestic pigeon. The phenomenon is confined to the 

 dorsal surfaces of the distal portions of the feathers ; it is not due to 

 diffraction, and Gadow's refraction-prism hypothesis is untenable. The 

 metallic colours are probably thin-plate interference colours or Xewton's 

 rings effects, which are produced where spherical pigment granules come 

 in contact with the outer transparent layer. The pigment also has the 

 very important function of absorbing light not reflected to the eye as 

 metallic colour. The colours seen without a Microscope are mixtures 

 of colours from innumerable small points. 



Fossil Plumage. t — C R. Eastman comments on the many chances 

 against the preservation of feathers or their impressions. Yet we know 

 the plumage of Archceojoteryx, Hesperornis, and Palceospiza. Moreover, 

 from the Upper Eocene limestone of Monte Bolca in the Veronese — a 

 marine horizon — a few feathers have been obtained, and Eastman de- 

 scribes a small fossil Carinate feather recently accpiired by the Museum 

 of Comparative Zoology at Cambridge. It is possible to distinguish 

 each separate barb and even the barbules. 



Respiratory Rhythm in Chameleon. J — MM. Couvreurand (lautier 

 have analysed the respiratory mechanism in Chamcdeo vulgaris with 

 the following result. The flank movements correspond to the respira- 

 tion ; they are slow, being one per minute at 20° C. There are three 

 pauses in the respiratory movement. After full inspiration there is a 

 short pause, then a half expiration followed by a long • pause of half a 

 minute or over, then the end of expiration, between which and the next 

 inspiration there is another pause. Raising the temperature effects a 

 shortening of the pauses. It is not known whether the pauses are 

 effected by the closing of the glottis or are independent of it. 



Variations of Toads. § — L. Camerano gives a detailed account of 

 the variations in Bufo viridis Laur., B. mauritanicus Schlegel, and 

 B. regularis Reuss. His memoir is an illustration of elaborate ' ; somato- 

 metry " work. 



New Apodous Amphibian from India. ||- — A. Alcock describes 

 Herpele fuller i sp. n. from Cachar, in the province of Assam. Three 

 other species are known, one of which occurs in Panama and another 

 in West Africa. This raises a problem in distribution, and the author 

 seeks for some light in comparing the distribution of the Cajciliidaa in 

 general with that of certain sublittoral genera of hermit-crabs. The 

 facts suggest the hypothesis of a "Tethyan Sea" or chain of arehi- 



* Mark Anniv. Vol., 1903, pp. 263-77 (1 pi.). 



+ Amer. Nat., xxxviii. (1904) pp. 669-72 (1 fig.). 



t Ann. Soc. Linn. T.von, 1. (1904) pp. 159-60. 



§ Mem. R. Aocad. Sci. Torino, liv. (1904) pp. 183-280. 



|| Ann. Nat. Hist., xiv. (1894) pp. 267-73 (1 pi.). 



