'NATURAL SYSTEMS. MACLEAY'S. 217 



be uninteresting to science. To the student we feel 

 assured it will be acceptable ; since no one has yet at- 

 tempted to place the subject in a clear light; and the 

 Horce EntomologiccB is now so scarce,, that few can hope 

 to consult its philosophic pages. We have also felt 

 desirous to place the value of Mr. MacLeay's discoveries 

 in their true light, and clearly to explain those funda- 

 mental principles of the natural system which he has 

 the high and undoubted honour of having discovered. 

 How far he may have been successful in the application 

 of these principles, belongs not to our present enquiry, 

 which regards the principles of natural classification,, not 

 the results of their application. 



(268.) In connection with the denomination or rank 

 assigned by Mr. MacLeay to some of his groups, a few 

 remarks are necessary, as they are not considered by him 

 in the same uniform light. In some of the diagrams 

 he has given to explain the affinities of the annulose 

 animals, the very same group which is called typical in 

 one, is made aberrant in another. Thus, on turning 

 to the diagram of the Annulosa*, we find that the Chilo- 

 poda and Thysanura are typical groups : but in the 

 diagram of the Mandibulata, the denomination and situ- 

 ation of the Thysanuriform type are changed ; it is no 

 longer typical, but aberrant ; while the Chilognathiform, 

 placed at p. 390. as aberrant, is now made typical : 

 this, of course, brings with it a complete change, not 

 only in the smaller circle which contains these types, 

 but in the situation of every other in these two dia- 

 grams. As nothing, so far as we can discover, is stated in 

 explanation of these contradictory denominations of the 

 same groups, we can only account for it, either by sup- 

 posing Mr. MacLeay not to have then discovered that 

 the same group which was external or typical in one 

 circle, was also external in another, or that, in the 

 eager and natural desire to make good his circle of the 

 Annulosa, he overlooked this transportation of his groups. 

 Certain, however, it is, that this oversight has not only 



* Hor. Ent. p. 390. 



