FLEMING. 557 



Division II. TOOTHLESS. 



SECTION I. OPERCULATED. Genera: Balanus, Coronula. 

 SECTION II. PEDUNCULATED. Genus, Lepas. 

 SECTION III. IMBRICATED. Genus : Chiton. 



But in 1820, when Dr. Fleming published the article 

 " Mollusca " in the same Encylopaedia, he had shaken off the 

 Linnaean yoke, and had become a follower of Cuvier, with- 

 out treading exactly in his steps, as if resolute not to wear 

 the livery of his master, while, at the same time, he derived 

 from him his sustenance and position. What led Dr. Fleming 

 truant and aside, as I deem his deviations from Cuvier to 

 have been, was the importance he attached to the binary 

 method of analysing the great classes of animals into their 

 less and lesser divisions, a method which may often be 

 called into useful aid when the search after a genus by 

 artificial devices is alone the object, but which adhered to 

 in any system that pretends to arrange animals according to 

 their affinities, as indicated by their general identity of 

 structure, and that was Cuvier's object, will sever far 

 asunder kindred races.* The truth of this remark is made 

 obvious by an examination of Dr. Fleming's method, which 

 we extract, as re-printed in his very valuable work, the 

 " Philosophy of Zoology," ann. 1822. 



* Dr. Fleming, in the preface to his " Philosophy of Zoology," has vin- 

 dicated his predilection for this binary method, in some remarks which are 

 worth quoting. " There is now much declamation ahout the worthlessness 

 of Artificial Systems, and the excellence of Natural Methods. But this 

 excellence is more apparent than real. Many of those natural groups which 

 are so much praised are ill defined, and it is even acknowledged by their ad- 

 mirers that precise limits cannot be assigned to them. Hence it frequently 

 happens that the definition of the group is applicable to a few genera only, 

 which are considered as its type, and does not embrace other genera which 

 are regarded as belonging to it, but beginning to assume the characters of 

 some of the other neighbouring groups. There is here the use of a method 

 where there is no precision, and a boasting that the plan of nature is fol- 

 lowed, when that plan is confessedly incomprehensible. Indeed, it often 

 happens that the admired natural method of one zoologist differs from the 

 censured artificial method of another, merely in the circumstance that dif- 

 ferent systems of organs have been made choice of as the basis of the re- 

 spective classifications. Unless zoologists, in the formation of their primary 

 groups, endeavour to determine those characters which all the members 

 possess in common, admitting only such marks into the definition, and prac- 

 tise the same method with all the subordinate divisions, the progress of the 

 science will be unsteady, the student will be startled at its contradictions, 

 and the revolutions in nomenclature become as frequent as the cultivators of 

 the science are numerous." 



