Historical 9 



are, however, three worms not included with the rest, namely, 

 Fasciola L., the newly defined genus Planaria Miiller, and Serpula 

 L. ; but it must be admitted that, taking into account the state of 

 knowledge at that time, these three were difficult genera to place 

 correctly in the scheme of classification. Miiller referred Fasciola 

 and Planaria to the Mollusca, and Serpula to the Testacea. He does 

 not appear to have known the work of Pallas on Serpula ; at any 

 rate, he did not refer to it in his synonymy. Miiller was the first to 

 use the presence of chaetae as the distinguishing character of a group 

 of worms. 



Blunienbach 1 pointed out that Vermes differ from Insecta not 

 only in the absence of antennae but also of jointed locomotor organs. 

 He was the first to state and emphasise this fundamental difference 

 between the jointed appendages of " Insecta " [i.e. Arthropoda] and 

 the feet of worms. His classification closely follows that of 

 Linnaeus. 



Barbut, 2 Bruguiere 3 and others, produced systematic memoirs 

 based largely on the Linnaean system and reproducing many of 

 its errors. The majority of treatises on natural history published 

 during the last third of the eighteenth century held tenaciously 

 to the Linnaean classification of the Vermes, and in the hands 

 of most workers this class was still in the same unsatisfactory 

 condition as it had been left by Linnaeus. The work of Pallas on 

 Serpula and the outline classification given by Miiller were the first 

 indications of the dawn of order, which, in the closing years of the 

 eighteenth century, broke upon the chaotic assemblage of Vermes. 

 In 1795 Ouvier communicated to the Societe d'Histoire naturelle of 

 Paris a memoir 4 on the circulation in " animaux a sang blanc," in 

 which he described the heart and blood-vessels of various molluscs, 

 and also gave a Table showing the nature of these organs in various 

 classes of animals. The work done in preparation for this memoir 

 brought clearly before him the characters which distinguish worms 

 from molluscs, and from this time forwards Cuvier separated these 

 two classes of animals. In his next memoir " Tableau elementaire 

 de 1'histoire naturelle des animaux " (Paris, An 6, = 1798) the two 



1 Handb. der Naturg., Gottingen (1799), 6 Aufl., p. 401. [1st Edit., 1779.] 



2 Genera Vermium, London (1783). 



3 Hist. nat. des Vers in Encyclop. method., Paris (1791). Bruguiere 

 established a new order in the class Vermes Vers Echinodermes to contain 

 the star-fishes, sea-urchins, etc. The other Vermes were left in the same 

 arrangement as in the Sy sterna. 



4 Bull, des Sci. par la Soc. Philom., Paris, i, An iii [1795], p. 91. 



