MEMOIR. XXXI 



would form a very useful and acceptable addition to a futui-e edition of 

 your Grammar of Entomology. 



" If I cannot give an unqualified assent to all your views, I tlilnk them 

 Avell Avorthy of attention, consideration and study. 



" You have often very happily illustrated what before was obscure, and 

 have pointed out some striking resemblances, or affinities, as it is the fashion 

 to call them. You have proved to my satisfaction the centrality of certain 

 groups or types of form, combining some of the characteristics of the sui-- 

 rounding groups, together Avith a character peculiarly their OAvn. This, it 

 appears to me, must be the key to affinities, if such exist. That there are 

 rerfUy seven great and perfectly natural groujis of insects, and that they 

 approach each other, as you have represented, appears undeniable. Divide 

 any one of them, and the parts lose their relative value Avhen compared 

 with the other groups. Whether there ever Avere, or ever will be, other 

 equally natural groups of insects, and — if so — Iioav they can be connected 

 Avith your circle, is more than I can tell. It seems to me, hoAVCA'er, upon 

 taking a more extended vieAV of nature, that living bodies are infinitely 

 varied in structure, and were 1 to be required to say in one word, Avhat 

 is the system of nature, I should answer, variety. We see only a part of 

 the series, the beginning and the end are lost to our vIcav — avc knoAv only in 

 part Avhat is — avc know but little of Avhat has been, and Ave knoAV nothing 

 of Avhat is to be. And yet to form a perfect, philosophical system, or 

 rather to trace out the Avhole plan of the Creator, Ave should have at once 

 before us all the living beings that ever have been, and ever avIII be created. 

 Hence all our attempts to discover a natural system, either in Zoology or 

 Botany, must fall far short of perfection. 



" AlloAv me again to make my acknowledgments for the unmerited honor 

 that you have conferred upon me, — and be assured that such notice froiii 

 one for whose valuable contributions to science I have a high respect, is a 

 source both of pride and of pleasure to 



" Your friend and servant, 



" T. W. Harris." 



