242 Dr. J. Young on the Malacostraca of Aristotle. 



of undetermined animals. It is true that no attempt at classifi- 

 cation can be found in Aristotle's writings; that the basis of 

 classification (viz. correct anatomical knowledge, by which the 

 affinities of animals could be recognized) was wanting; that 

 Aristotle has expressly argued against the use of a negation as 

 a character, and in one passage (De Part. i. 3) even mentioned 

 (directly or indirectly, according to the lection adopted) this 

 very case as one of great difficulty. Nevertheless the so frequent 

 use of these terms, always with the same precise meaning, and 

 the numerous physiological results of the qualities they repre- 

 sent, seem to indicate that to Aristotle they had more than a 

 merely symbolical value. The implication of a positive character 

 under the negative phrase would remove some part of the incon- 

 sistency attaching to principles so clearly and justly condemned, 

 and so freely followed. The following passage seems to supply 



such a positive character: — \eyco &' avakoyov oti. tois fiev 



alfxa, to?9 Be to avakoyov rrjv avTrjV e%ov Bvvafjbiv rjvirep rots 

 ivalfioi? to al/jua (De Part. i. 5). The term bloodless would 

 thus be a brief expression for animals having only the analogue 

 of blood — an imperfect somewhat which had not undergone the 

 "cooking" process necessary for the elaboration of blood proper. 

 For this, avai/xa was the only word in the language. Without, 

 however, insisting on this (perhaps overstrained) interpretation, 

 I would point out that this division of the animal kingdom is 

 superior to the unphilosophic one, Vertebrata and Invertebrata, 

 to which it exactly corresponds; for while Lamarck proposed 

 these terms with the full knowledge of the great structural dif- 

 ferences included under the negation, Aristotle ascribes to his 

 bloodless animals the common character of want of brain and 

 viscera, as well as other more fanciful metaphysical qualities. 

 It is a question worthy of investigation how far the doctrine of 

 analogies applies to the organs described in the bloodless ani- 

 mals ; but as its consideration will best come after the anatomy 

 of all these groups has been described, I leave it in the mean- 

 time, my present purpose being only to supply some of the data 

 for the solution of this and other interesting points in the his- 

 tory of ancient science. 



The bloodless animals are, as already said, the Malakia, Mala- 

 costraca, Ostracoderma, Entoma, and a group of diverse forms 

 which cannot be included under one common form (aspect, eZSo?). 

 The diagnosis of these groups may be thus tabulated : — 



1. Malakia soft parts external = Cephalopoda. 



2. Malacostraca "I . , f external \ flexile = Crustacea. 



3. Ostracoderma J " " mternal \ covering J brittle = Conchifera. 



4. Entoma bod) r homogeneous =Insecta. 



The separation of Crustacea from Insecta has been urged as 



