ON THE USE OF SOME WORDS 7 



The word " polype " used in the sub-title of his work 

 needs a few words of comment at this stage, as it also has 

 changed its meaning to some extent. 



The Greek word 7ro\v7rou<i (Latin polypus) or " many- 

 footed," was applied by Aristotle and other ancient writers 

 to the cuttlefish or octopus, and from this word was derived 

 the French word " poulpe," signifying a cuttlefish. When 

 the naturalists of the eighteenth century examined the living 

 corals and saw emerging from the outer crust a number of 

 small animals of tubular form, with a mouth at the free 

 extremity surrounded by a circlet of tentacles, they were 

 reminded of the cuttlefishes and octopuses with which they 

 were well acquainted. 



Thus Peyssonnel, writing about the Precious coral, said 

 that he had discovered that " la fieur de cette pretendue 

 plante n'etait au vrai, qu'un insecte semblable a une petite 

 ortie {i.e. sea-anemone) ou poulpe." And Trembley, in the 

 account of his remarkable observations on Hydra, refers to 

 it as the " polype d'eau douce." The great French entomo- 

 logist Reaumur, however, who, assisted by Bernard de 

 Jussieu, repeated Trembley's experiments on Hydra, must be 

 held responsible for the establishment of the name polype 

 for these animals because " leurs cornes sont analogues aux 

 bras de I'animal de mer qui est en possession de ce nom " 

 {i.e. poulpe). 



When later observations showed that the polyps of 

 the Hydrozoa differed in structure from the polyps of the 

 Anthozoa and these in their turn from the polyps of 

 the Polyzoa, an attempt was made to restrict the use of the 

 term to the polyps of the Anthozoa. Milne-Edwards, how- 

 ever, protested against this restriction as being prejudicial 

 to the interests of science, and said that the word could be 

 usefully maintained for the soft and contractile parts of the 

 Polyzoa, the Hydrozoa, the Alcyonaria, and the Zoantharia, 

 and should not be employed for one or more zoological 

 groups to the exclusion of others. 



In modern times the word polyp has still a vague 

 and ill-defined meaning. It is applied to the isolated fresh- 

 water Hydra and to the animals that construct the horny 



