SCIENCE-GOSSIP. 



301 



larvae at Eastwood. H. genistae, Southend and 

 Pitsea ; not common. 



Xylocampa areola. Eastwood; not common. 



Calocampavetustt. Southend; scarce. C. exoleta, 

 Southend ; not uncommon. 



Xylina socia. Southend ; very scarce. 



Cucullia chamomiUae and C. umbratica, occasionally 

 on posts and fences. 



Gonoptera libatrix, occurs pretty freely ; larvae 

 on sallow at Eastwood. 



Plusia chrysitis, not common at Southend gas- 

 lamps. P. festucae, once only, on sugared reeds at 

 Benfleet. P. gamma, abundant. 



Heliaca tenebrata, occasionally at Benfleet and 

 Eastwood. 



Acontia luctuosa. Eastwood ; a very lively ex- 

 ample at one of the railway station lamps at 

 Benfleet. 



Era stria fasciana, no common at Eastwood. 



Phytometra viridxria. Eastwood ; not common. 



Euciidia mi, very common on the salt marshes ; 

 the curious larvae frequently seen. E. glypltica, 

 Leigh and Southend slopes ; not uncommon. 



Catocala nupta, generally distributed and rather 

 common. 



Rivitla sericealis. Leigh slopes ; not uncommon. 



Zanclognatha grisealis, rather common at East- 

 wood. Z. tai sipennalis, Eastwood ; not common. 



Herminia cribralis, Shoebury; common at Ben- 

 fleet. 



Peeliypogou barbahs, a very common insect at 

 Eastwood. 



Hypena rostralis, at sugar at Southend. 11. pro- 

 boscidalis, occasionally at Southend. 



Hype-nodes costaestrigalis, once only, at Eastwood. 

 {To be continued.) 



COLOUR IN NATURE. 



By Wilfred Mark Webb, F.L.S. 



TT is an old cry that the titles of books are often 

 a trifle misleading, and " Colour in Nature " (•), 

 by Marion J. Newbigin, may again call it forth. 

 To one who has borrowed this heading for his 

 talks in lecture form about colour in the landscape, 

 and from an environmental point of view which 

 the words obviously suggest, there is at first a 

 slight disappointment to find that the book in 

 question treats the subject almost entirely from an 

 internal point of view. Indeed it is not until the 

 last chapter is reached that the interesting theories 

 are discussed which explain how colour may come 

 to be useful to its possessors in the struggle for 

 existence. When reading the book, however, any 

 desire that it should be a popular addition to those 

 " which treat of the external aspects of the colours 

 of organisms," fades before the pleasure of finding a 

 solid contribution to science, bringing together the 

 facts and fancies which bear upon " the meaning of 

 colour in the functional economy of the organism," 

 and summarizing what is known about the com- 

 position of pigments, as well as the distribution of 

 these and structural colours in the world of life. 

 Such a work must manifestly be a compilation ; 

 but all honour is due to conscientious compilers 

 in the field of biology. They bring the results 

 of deep study and a wide grasp of their subject 

 to bear upon the labour they impose upon 

 themselves, labour which is ever increasing until 

 the work is completed. Their reward is usually 

 but the satisfaction of having done their best and 

 made the way of others easier by their task. For 



(') "Colour in Nature," by Marion J. Newbigin, D.Sc. 

 5 in. x 7$ in. 337 pp. with 4 figures. (London: John Murray, 

 50a, Albemarle Street, 1898.) 7s. 6d. 



such work is often sneered at as " mere compila- 

 tion " ; and as the personal element comes to the 

 fore with some force in the arrangement of 

 material, a built-up book offers a fine field for 

 criticism to those who would have done it differ- 

 ently if they had followed up such an idea, but 

 did not. 



The following schemes, giving an idea of the 

 kinds of colour, as also the examples illustrating 

 them, are taken from the opening chapters, in 

 which an interesting paragraph upon the pro- 

 duction of light by organisms finds a place. 



Structural Colours. 



(1) Those not dependent upon the presence of a 

 pigment : — 



(a) Due to total reflection : white colour of 

 some flowers, some feathers, and of hair. 



(b) Due to striation of surface or thin plates : 

 iridescence of bristles and cuticle of worms, 

 and of mother-of-pearl. 



(2) Those dependent upon the presence of a 

 pigment : — 



(a) Unchanging in reflected light, and not 

 readily distinguishable from pigmental 

 colours (objective) : blue and green appear- 

 ance of feathers. 



,(b) Changing in tint according to the angle 

 at which they are viewed (subjective) : 

 metallic colours of many birds and insects. 



The state of our knowledge of the chemical 

 composition or of the physiological function of 

 pigments does not at present allow a classification 

 of them upon either of these bases, and colourirg 



