704 ON CONCRETIONS, SPICULES, ETC. [ch. 



and then passes it out again*. In another case a thread of shellac, 

 laid on a drop of chloroform, is drawn in and coiled within it: 

 precisely as we may see a filament of Oscillatoria ingested by an 

 Amoeba, and twisted and coiled within its cell. It is all a question 

 of relative surface-energies, leading to different degrees of " adhesion " 

 between the chloroform and the splinter of glass or its shellac 

 covering. Thus it is that the Amoeba takes in the diatom, dissolves 

 off its proteid covering, and casts out the shell. 



Furthermore, as the whole phenomenon depends on a distribu- 

 tion of surface-energy, the amount of which is specific to certain 

 particular substances in contact with one another, we have no 

 difficulty in understanding the selective action which is very often 

 a conspicuous feature in the phenomenon")*. Just as some caddis- 

 worms make their houses of twigs, and others of shells and again 

 others of stones, so some Rhizopods construct their agglutinated 

 "test" out of stray sponge-spicules, or frustules of diatoms, or 

 again of tiny mud particles or of larger grains of sand. In all these 

 cases, we have to deal with specific surface-energies, and also 

 doubtless with differences in the total available amount of surface- 



* Rhumbler, Physikalische Analyse von Lebenserscheinungen der Zelle, Arch, 

 f. Entw. Mech. vii, p. 250, 1898. 



t The whole phenomenon has been described as a "surprising exhibition of 

 constructive and selective activity," and ascribed, in varying phraseology, to 

 inteUigence, skill, purpose, psychical activity, or "microscopic mentality": that is 

 to say, to Galen's t(x^lk7] (pvais, or "artistic creativeness " (cf. Brock's Galen, 1916, 

 p. xxix); cf. Carpenter, Mental Physiology, 1874, p. 41; Norman, Architectural 

 achievements of Little Masons, etc., Ann. Mag. Nat. Hist. (5), i, p. 284, 1878; Heron- 

 Allen, Contributions ... to the study of the Foraminifera, Phil. Trans. (B), ccvi, 

 pp. 227-279, 1915; Theory and phenomena of purpose and intelligence exhibited by 

 the Protozoa, as illustrated by selection and behaviour in the Foraminifera, Journ. 

 R. Microsc. Soc. 1915, pp. .547-.557; ibid., 1916, pp. 1.37-140. Sir J. A. Thomson 

 {New Statesman, Oct. 23, 1915) describes a certain little foraminifer, whose proto- 

 plasmic body is overlaid by a crust of sponge-spicules, as "a psycho-physical 

 individuality, whose experiments in self-expression include a masterly treatment of 

 sponge-spicules, and illustrate that organic skill which came before the dawn of Art." 

 tSir Kay Lankester finds it "not difficult to conceive of the existence of a mechanism 

 in the protoplasm of the Protozoa which selects and rejects building-material, 

 and determines the shapes of the structures built, comparable to that mechanism 

 which is assumed to exist in the nervous system of insects and other animals which 

 'automatically' go through wonderfully elaborate series of complicated actions." 

 And he agrees with "Darwin and others [who] have attributed the building up of 

 these inherited mechanisms to the age-long action of Natural Selection, and the 

 survival of those individuals possessing qualities or 'tricks' of life-saving value," 

 ■Iniirn. R. Microsc. Soc. April, 1916, p. 136. 



