August 7, 19 13] 



NATURE 



599 



edge of the circle of light, and the parts respectively 

 above and below appear to be separated by a con- 

 siderable interval ol water surface. When the portion 

 above the water is white, as in a gull, it is difficult 

 to detect against the sky. The above remarks only 

 refer to open water, and 1 will illustrate how a 

 wading bird is concealed against the image of a reed- 

 bed many yards behind him. Looked at from below 

 the markings on a heron are in bold upright lines, for 

 the plumage is greyish-white with black patches on 

 each side of the head, and the black patches on the 

 shoulders appear continuous with the black primaries 

 of the wings. Seen against an open sky, the white 

 parts of the wading heron blend with the sky, but 

 the black parts stand up in bold relief. The head and 



Stuffed heron with neck straight out prepared to strike a fish. 

 Appearance of heron under ihe water. (Fiom life.) 

 "1 h,- same bird as he a) prars on the edge of the circle of ligl 

 tree 160 ft. away and the no.ly of the bird appear to be one. 

 Reeds were then placed 5 ft. behind the bird, and now his head 



When the above photographs 



: taken the le 



,.f the 



shoulders of the bird are seen on the edge of the 

 circle of light, but so also is the reed-bed many yards 

 behind. The reeds, seen as perpendicular images, and 

 the perpendicular markings on the heron blend, and 

 thus make the bird inconspicuous. 



I hay.- referred to white as a concealing agency. 

 Black objects, when they retain air-bubbles on their 

 surface, also become reflectors under the water. The 

 black water-spider under a leaf appears green and is 

 lost to sight. A vvaterhen swimming on the surface 

 in the area of total reflection reflects the green weeds 

 below, and becomes difficult to discern against the 

 surface which is reflecting the same colour. 



In conclusion, I will refer to reflection as a revealing 



NO. 2284, VOL. 91] 



factor. I have already illustrated this point with the 

 anemone. I now show a slide of a shoal of young 

 rudd wheeling round, and as they turn each fish is 

 revealed as a flash of light as he catches the light 

 fn mi above. 



Among diving birds the cormorant does not retain 

 air bubbles in his feathers to the same extent as the 

 loose-plumaged vvaterhen, yet by reflection he appears 

 light or dark, ac< ording to (he nature of the bottom 

 over which he is swimming. When, however, the 

 cormorant dives his track is marked by a series oi 

 brilliant flashes of light. 



Now this bird when swimming on the sui i. 

 the habit of dropping his head under water at regular 

 intervals sings do the same. Seen from below , evi ry 

 lime lie dues this, there is a flash of 

 light not unlike the Hash, from a 

 silvery fish turning. It is quite pos- 

 sible that fish, such as pollock and 

 codling, are attracted by this flash, 

 .and thus swim towards their 

 destroyer. These flashes of light are 

 still better shown in the ca 

 penguin, and this I illustrate with 

 individual pictures cu1 out of a kine- 



111 *raph him. 



I have had to leave the subject oi 

 refraction of light on -the present' 

 occasion; first, because time does 

 not permit of my dealing- with it, 

 and, secondly, because during the 

 last fortnight 1 have tested all my 

 experiments at Tort Erin, and some 

 of the results have made me recon- 

 sider the conclusions at which I had 

 arrived with- regard to the refraction 

 of light in its relation to marine 

 organisms. 



TFCHXICAL EDUCATION 

 FOR INDIAN STUDENTS. 



THE report of a Commii 

 pointed by the Secretary of 

 State for India to inquire into the 

 system of State technical scholar- 

 ships established by the Government 

 of India in 1004, has been published 

 as a Blue-book (Cd. 6S07). On 

 March 27, 1912, the Secretary oi 

 State appointed a Committee "to 

 inquire and report as to the facilities 

 available for Indian students for 

 industrial and technological training 

 in this country, with special refer- 

 ence to the system of State technical 

 scholarships" established by the 

 Government of India in 1904." The 

 Committee was constituted as 

 follows :— Sir Theodore Morison, 

 K.C.I. E. (chairman), Sir K. G. Gupta, K.C.S.I., Mr. 

 J. H. Reynolds, Prof. W. E. Dalby, Mr. P. H. Dum- 

 bell (secretary), Mr. R. E. Field (assistant secretary). 

 I'll.' Committee held its first meeting at the India 

 Office on May 9, 1912, for the purpose of discussing 

 the itinerary, "and considering questions of procedure. 

 On various occasions the Committee visited Gl isgow, 

 Leeds, Manchester. and Birmingham, where 

 they received evidence from the higher educa- 

 tion authorities, and visited the various labora- 

 tories, and so on, devoted to technical educa- 

 tion. Altogether during the provincial meet- 

 ings the Committee took evidence from seventy-five 

 wi'nesses, of whom twenty-nine were professors and 



a foot below 



