474 MARIA M. OGILVIE GORDON. 



"Thus there exists, contrary to the opinion of Gardiner 

 (1900)^ who was not able to disclose it in his preparations, an 

 organic substratum in the skeleton of the " Coralliaries." 



" Contrary again to the opinion of Dnerden (1904), who 

 admits the existence of a fundamental substance, but who 

 considers it as homogeneous, this substance has a histo- 

 logical constitution, well characterised, which realises all the 

 appearances of a cellular structure. 



"These facts much depreciate in value Koch's hypothesis 

 of extracellular secretion. They seem to fully justify Heider, 

 who considers the ' polypier ' as formed by the accumula- 

 tion of calcified cells. 



"At the same time this is not so; the calcareous scales 

 whose juxtaposition forms the corallum are not the skeletons 

 of calicoblasts. They have not the value of cells." 



Before proceeding further with M. Krempf's description a 

 few remarks may be made regarding these preliminary 

 statements. 



The first statement that M. Krempf "finds it easy to 

 verify that the skeletal parts are formed by the 

 imbrication of a multitude of small calcareous 

 scales" is a corroboration of observations which were 

 unknown to zoologists previous to the publication of my 

 work ou the " Madreporaria." * 



That paper for the first time gave a description and 

 illustrative figures of the minute skeletal elements which 

 everywhere compose the corallum. I described these ele- 

 ments as " calcareous scales," and showed the imbricated 

 manner of their apposition with one another, and their 

 various shapes and positions at different parts of the corallum 

 (1. c, pp. 114, 115, 127; figs. 7 A— c; 8 a— c, etc.). 



The references made by M. Krempf to von Heider's work 

 are somewhat ambiguous, as they lead one to infer that von 



1 M. M. Ogilvie, "Microscopic and Systematic Study of Madreporarian 

 Types of Corals," ' Phil. Trans. Roy. Soc.,' London, vol. 1S7 (1S9G), B, 

 pp. 83 — 34:5. Also see my monograph on the " Stranibcrgcr Korallen" 

 (PaliEontographica, Stuttgart, 1897, Suppl. ii, No. 7, pp. 73—282, pis. vii— 

 xviii). 



