BOWERBANK ON CIRCULATION. 239 



and I see his "Essay" handled so tenderly, and treated with 

 so much respect, that I flatter myself these observations will 

 not altogether escape his notice, and I may reasonably expect 

 that I shall draw on myself his angry reply. I wish now 

 most positively to state, that I shall decline a controversy; 

 and to all who may desire to commence one, I merely say, 

 reperuse tJiis. 



It is scarcely allowable thus to point out the errors, without 

 making any allusions to the merits of a work: permit me, 

 therefore, to add, that I have never seen any summary of the 

 characters of the diflferent classes of insects given in so clear, 

 concise, and unexceptionable a manner, as in Mr. Newman's 

 table ; neither did I ever read a work on natural history con- 

 taining such profound ideas, and displaying such varied and 

 great talent, as the one, the main theory of which it has been 

 my endeavour to point out as being completely imaginary. 

 How often is this the case ! how often does talent, like the 

 " ignis fatuus," dazzle to mislead. 



I am, Sir, 

 Your subscriber, and generally your admirer, 



Clericus. 

 October 1, 1S32. 



Art. XXV. — Observations on the Circulation of the Blood 

 in Insects. By James Bowerbank, Esq., F. G. & Z. S. 



The larva of the Ephemera marginata^ is the insect which 

 best exhibits the general circulation of the blood, and is the 

 one which has been the principal subject of the following 

 observations. It is figured and described in Dr. Goring and 

 Mr. Pritchard's "Microscopic Illustrations;" but, for my 

 first introduction to the living larva, I am indebted to my 

 friend, Mr. Tulley, with one of whose splendid instruments 

 my observations have been made. These larvae may be found 



» It does not appear quite certain of wliat particular species of ephemera 

 the insect described here is the larva. — Ed. 



