Historical 9 



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

 FftHnola T-., tlio newly defined genus rhniarui Miiller, and Serpvia 

 L. ; lull it must be a(hnitted that, lakint; into aecount the state of 

 knowledge at tliat time, these tiuee were diflicult genera to place 

 correctly in the scheme of classification. Miiller referred Fasciola 

 and rianaria to the Mollusca, and Scrpula to the Testacea. He does 

 not appear to have known tlie work of Pallas on Serjmla ; 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 cliaracter of a group 

 of worms. 



Blumeuhach ^ pointed out that Vermes differ from Insecta not 

 only in the aljsence of antennae hut also of jointed locomotor organs. 

 He was the first to state and emphasise this fundamental difference 

 hetween the jointed appendages of " Insecta " \i.c. Arthropoda] and 

 the feet of worms. His classification closely follows that of 

 Linnaeus. 



Barhut,- Bruguiere^ and others, produced systematic memoirs 

 Ijased largely on the Linnaean system and reproducing many of 

 its errors. The majority of ti-eatises on natural history published 

 during the last third of the eighteentli century held tenaciously 

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

 of most workers this class was still in the same unsatisfactory 

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

 Scrjmla and the outline classification given l)y Miiller were the first 

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

 eiglitcenth century, broke upon the chaotic assemblage of Vermes. 

 In 1795 Cuvier communicated to tlie Societe d'Histoire naturelle of 

 Paris a memoir* 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 for\vards Cuvier separated these 

 two classes of animals. In his next memoii- — " Tableau elementaire 

 de I'histoii-e naturelle des animaux " (Paris, An T), = 1798) — the two 



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



- Genera Vermium, London (1783). 



^ Hist. nat. des Vers in Encyclop. method., Parin (1791). Brugui^rc 

 established a new order in the class Vermes — Vers I^chinodermes — to contain 

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

 arrangement as in the Systema. 



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



