IX] ON SPHERULITES OR CALGOSPHERITES 423 



they very closely resemble the little calcareous bodies in the 

 tissues of a trematode or a cestode worm, or in the oesophageal 

 glands of an earthworm*. 



When the albumin was somewhat scanty, or when it was mixed 

 with gelatine, and especially when a little phosphate of lime was 



Fig. 199. Large irregular calcareous concretions, or spicules, deposited in a piece 

 of dead cartilage, in presence of calcium phosphate, (After Harting.) 



Huxley pointed out that the mode of formation, while at first sight "irresistibly 

 suggesting a cellular structure,... is in reality nothing of the kind," but ^'is simply 

 the result of the concretionary manner in which the calcareous matter is deposited " ; 

 ibid. art. "Tegumentary Organs," vol. v, p. 487, 1859. . Quekett (Lecttires on 

 Histology, vol. n, p. 393, 1854, and Q. J. M. S. xi, pp. 95-104. 1863) supported 

 Carpenter; but Williamson (Histological Features in the Shells of the Crustacea, 

 Q. J. M. S. VIII, pp. 35-47, 1860) amply confirmed Huxley's view, which in the 

 end Carpenter himself adopted (The Microsccpe, 1862, p. 604). A like controversy 

 arose later in regard to corals. Mrs Gordon (M. M. Ogilvie) asserted that the coral 

 was built up "'of successive layers of calcified cells, which hang together at first by 

 their cell-walls, and ultimately, as crystalline changes continue, form the individual 

 laminae of the skeletal structures" {Phil. Trans, clxxxvii, p. 102, 1896): whereas 

 V. Koch had figured the coral as formed out of a mass of "Kalkconcremente" 

 or "crystalline spheroids," laid down outside the ectoderm, and precisely similar 

 both in their early rounded and later polygonal stages (though von Koch was not 

 aware of the fact) to the calcospherites of Harting (Entw. d. Kalkskelettes von 

 Asteroides, Mitth. Zool. St. Neapel, in, pp. 284-290, pi. xx. 1882). Lastly Duerden 

 shewed that external to, and apparently secreted by the ectoderm lies a homo- 

 geneous organic matrix or membrane, "in which the minute calcareous crystals 

 forming the skeleton are laid down" (The Coral Sidernstraea radians, etc.. Carnegie 

 Iii.st. Washington, 1904, p. 34). Cf. also M. M. Ogilvie-Gordon, Q. J. 31. S. xlix. 

 p. 203. 1905, etc. 



* Cf. Claparede. Z. f. w. Z. xix, p. 604. ISfiO. 



