RED OR PRECIOUS CORAL. 9 



workers, while a certain amount of secrecy still haunts the 

 pursuit. Moreover, the trials of such a life are not few. Even 

 with every advantage it is by no means easy to secure specimens 

 that will live, for the tangles and other instruments of capture 

 inflict injuries which in warm weather prove fatal. Lacaze 

 Duthiers was most successful by selecting uninjured specimens 

 on stones, and suspending them in vessels of sea-water. 



Like all the members of the group Alcyonaria, to which red 

 coral belongs, the polyps on its surface have eight pinnate arms, 

 but instead of being red, or, as some of the older authors called 

 them, "flowers of blood," they are pale and transparent. When 

 contracted the surface of the coral is dotted with little elevations 

 marked by deep radiate grooves, and from each of these, in 

 sea-water, a polyp by-and-by expands. These polyps of the red 

 coral were the flowers of Marsigli,* and about which, in the 

 earlier days of Peyssonnel's discovery, so many opposing views 

 were broached. The hollow, pinnate tentacles (with thread- 

 cells) surround the mouth, which is in the centre, being ciliated, 

 and send currents of water (bearing food) into the digestive system. 

 Around the latter are eight radiating lamellae (mesenteries) and 

 other organs. The polyps, moreover, are dimorphic (autozoids 

 and siphonozoids, the latter without ova or generative organs). 

 These polyps thus resemble those of the common Alcyonium 

 digitatum, the "dead men's fingers and toes" of the fishermen, 

 yet it is remarkable that in a country of marine zoologists like 

 Britain scarcely a single figure representing these beautiful 

 polyps in their natural condition exists, for Prof. Hickson does 

 not figure a fully expanded polyp in his excellent brochure on 

 Alcyonium,i whilst the figures of the expanded polyp in his 

 finely illustrated Memoir! also lack the beauty of the perfectly 

 healthy example. Prof. Hickson, indeed, explains that when at 

 Plymouth he never succeeded in getting Alcyonium to expand to 

 his satisfaction, even the figure in the recent Cambridge Natural 

 History (1906) being indifferent, for it apparently has been taken 

 from a specimen by no means vigorous, and the striking diffe- 



* They essentially differed, however, as Lacaze Duthiers pointed out, for 

 when touched they contract. 



f L. M. B. C. Memoirs, v. 1901. 



I Quart. Journ. Micros. Sc. vol. xxxvii. pis. 36 and 37. 



