6 THE IIYDROIDA IN GENERAL. 



The only hydroid which, up to this time, had been examined in a living state with results 

 of any value to seience was the Tiibularia indivisa, which, as already mentioned, had been studied 

 by De Jussieu on the coast of Normandy ; a most important accession, however, to our know- 

 ledge of the IIydroida was now about to be made by the observations of Ellis, 



John Ellis was a London merchant devoted to the study of natural history, which he pur- 

 sued in the intervals of his mercantile labours, with an enthusiasm and a success which renders 

 his name famihar to every student of the Hydroida. He was elected a Fellow of the Royal 

 Society, and was awarded the Copley Medal in recognition of the esteem in which his researches 

 were held by that body. 



An examination of dried specimens of various hydroids had already led Ellis to suspect that 

 these plant-like productions really belonged to the animal kingdom, and determined him to study 

 them in a living state. With this view he repaired with his microscope to the Island of 

 Sheppey, and some other parts of the south-eastern shores of England, accompanied by Mr. 

 Brooking, a distinguished painter of sea-pieces, and by the celebrated botanical painter Ehret. 

 He had there abundant opportunity of studying a great number of living hydroids, and soon 

 convinced himself that " these apparent plants were ramified animals in their proper skins or 

 cases." In this remarkable assertion we have the first philosophic expression of the true nature 

 of the fixed plant-like hydroids, and thus was finally settled the animality of these organisms. 

 The results of his observations were published in 1755, in a work" whose beautiful and accurate 

 figures and admirable descriptions render it at this day indispensable to the student. 



Nothing was now wanting to produce general conviction of the animality, not only of the 

 true corals, but of all those flexible, plant-like productions whose external form had so long 

 caused their real nature to be overlooked. Even Linnaeus himself was at last convinced by the 

 discoveries of Ellis, and now declared himself a believer in their genuine animality. 



Besides the generally very expressive vernacular names employed by Ellis, his species are, 

 in accordance with the usual practice of the day, indicated by short Latin descriptions rather than 

 by systematic designations. Linnasus's grand invention of the binomial nomenclatiu'e was, 

 however, making its way among systcmatists. The ' Systema Naturas' had already passed 

 through several editions, and in 1766 Ave find the various species of Hydroida then known 

 enumerated by Pallas under their binary designations in his admirable ' Elenchus Zoophytorum.'- 

 In this work the species are characterised by a precision which leaves little to be desired ; a 

 complete synonomy is prefixed to each, and in their arrangement the celebrated Prussian natu- 

 ralist affords evidence of an insight into those affinities on which the more natural classifications 

 of subsequent systematists have been based. 



In the tenth fasciculus of his ' Spicilegia Zoologica,'^ published in 1774, Pallas describes and 



^ John Ellis, ' Au Essay towards a Natural History of the Corallines and other jMariue pro- 

 ductions of the like kind commonly found on the coasts of Great Britain and Ireland. To which is 

 added the description of a large Marine Polype taken iiear the North Pole by the Whale-fishers in the 

 summer of 1753.' London, 1755. 



" Petr. Sim. Pallas, ' Elenchus Zoo[ihytorum sistens generum Adumbratioiies generaliores et 

 specierum cognitarum succinctas descriptiones enm selectis Auctorum syuonymis.' Hagie-Comit., 1766. 



' Petr. Sim. Pallas, ' Spicilegia Zoologica quibus novse imprimis obscures Animalium species 

 iconibus, descript. atque commentariis illustrantur,' torn, i, fasc. i — x, Berolini, 1767 — 1774; tom. ii, 

 fasc. xi — xiv, Berolini, 177G — 1780. 



