452 Pauli, W. u. Samec, M., Ueber LûÑslichôÙkeitsôÙbeeinôÙflû¥sôÙsung von Elektrolyten durch EiweisskûÑrper, Biochem. Zeitschr. XVII, p. 235, 1910. Some of these results were known much earlier; cf. Fokker in Pflû¥gerãs Archiv, VII, p. 274, 1873; also Irvine and Sims Woodhead, op. cit. p. 347.
453 Which, in 1000 parts of ash, contains about 840 parts of phosphate and 76 parts of calcium carbonate.
454 Cf. Dreyer, Fr., Die Principien der Gerû¥stbildung bei Rhizopoden, Spongien und Echinodermen, Jen. Zeitschr. XXVI, pp. 204ã468, 1892.
455 In an anomalous and very remarkable Australian sponge, just described by Professor Dendy (Nature, May 18, 1916, p. 253) under the name of Collosclerophora, the spicules are ãgelatinous,ã consisting of a gel of colloid silica with a high percentage of water. It is not stated whether an organic colloid is present together with the silica. These gelatinous spicules arise as exudations on the outer surface of cells, and come to lie in intercellular spaces or vesicles.
456 Lister, in Willeyãs Zoological Results, pt IV, p. 459, 1900.
457 The peculiar spicules of Astrosclera are now said to consist of spherules, or calôÙcoôÙspheôÙrites, of aragonite, spores of a certain red seaweed forming the nuclei, or starting-points, of the concretions (R. Kirkpatrick, Proc. R. S. LXXXIV (B), p. 579, 1911).
458 See for instance the plates in Thûˋelãs Monograph of the Challenger Holothuroidea; also Sollasãs Tetractinellida, p. lxi.
459 For very numerous illustrations of the triradiate and quadriradiate spicules of the calcareous sponges, see (int. al.), papers by Dendy (Q. J. M. S. XXXV, 1893), Minchin (P. Z. S. 1904), Jenkin (P. Z. S. 1908), etc.
460 Cf. again Bûˋnardãs Tourbillons cellulaires, Ann. de Chimie, 1901, p. 84.