HEKTFORDSniRE NATURAL HISTORY SOCIETT. XXXIX 



Tho following: pnppr Tras read : — 



" Tho Agricultural Geology of Hertfordshire." By J. Yiucent 

 Elsdcn, B.Sc, F.C.S. {Transactions, Vol. II, p. 145.) 



Maps of the solid geology, the superficial geology, and the soils 

 of Hertfordshire were exhibited by Mr. Elsden in illustration of 

 his paper. 



OUDINART MeETIXG, 21 ST DECEMBER, 1882, AT HoDDESDON. 



RiCHAUD B. Croft, Esq., E.N., F.L.S., F.R.M.S., in the Chair. 



^Ir. John Callaway, Norris Lodge, Hoddesdon, and Mr. Richard 

 Lydc'kker, E.A., F.G.S., F.Z.S., The Lodge, Harpcnden, were pro- 

 posed as Members of the Society. 



The following paper was read : — 



" The Colour of Animals in Relation to their Habits." By 

 F. M. Campbell, F.L.S., F.Z.S., F.R.M.S. 



Mr. Campbell commenced his paper by pointing out that one of the first 

 principles a naturalist felt called upon to admit was that no single creature lives 

 only for itself. The whole imiverse is but one chain of mutual dependency. 

 Different animals are called upon from time to time to perform the most various 

 and the strangest functions for others ; indeed, the destiny of a great number of 

 them is to provide food for others, and this naturally involves a tremendous 

 sacrifice of life. But the economy of Nature is not based on the success of any 

 single individual or principle, but on the result of a great number of averages 

 taken from a great number of cases ; and just in the same way as in mechanism 

 there is no stability without two opposing forces, so stability in Natm'e is the 

 sum of a great number of antagonistic forces. 



RefeiTmg to the protective powers of animals, he said that when it was con- 

 sidered that the chances were very much against any single creature surviving to a 

 certain age, and yet that the continuance of its species was necessary to support 

 the life of other creatures, it would be seen that there must be some protection 

 for those animals, and that they must have enormous powers of repi-oducing 

 themselves. Thus it was found that, roughly speaking, the humbler the creature 

 was in the scale of life, the more rapid was its power of reproduction. The 

 means of protection which animals possess were very various, and were governed 

 to a great extent by their habits. There was the power afforded by weapons- of 

 self-defence, involving muscular activity and size, which were not within the 

 reach of every creature. There was the power afforded by great agility or rapid 

 flight, and this again was not within the reach of great numbers. Then there 

 was the power which some creatures have of making themselves disagreeable to 

 others as food ; and there was also the power of concealment, which was 

 greatly increased by colour — when the colour of the creature resembled that 

 of its immediate surrounchngs. Thus, commencing with water-life, he pointed 

 out that the crab, shrimp, lobster, and sole, in tlieir native state, have each a 

 protective power from their colour being similar to that of their surroundings ; 

 and that the same can be said even of the roach, dace, and other fish with brilliant 

 scales. A reflected beam of light may attract a pike to its prey, but it is also 

 calculated to produce the momentary dazzling effect which we ourselves experience. 

 The very metallic lustre which gives back the treacherous rays produces, when 

 viewed from other directions, a liquid appearance which is well adapted for con- 

 cealment in water. In the case of some creatures of brilliant colour — as for 

 instance some kinds of the sea -cucumber, whose bodies are covered with a number 

 of anchor-shaped spicules — their brilliant colour acts as a warning to others 

 wliich might wish to devour them. Other species allied to these are encrusted 

 with a hard deposit, so that fish will not attempt to eat them ; while others 



