PARKES — RESPIRATION OP INSECTS. 417 



who discuss pre-historic man in Europe knew a little more of his 

 analogue in America. The subject is a tempting one, but I must 

 close this notice, already too long for the space I should devote 

 to it, by remarking, that the relations in America of the short- 

 headed and long-headed races of men are by no means dissimilar 

 from those of the two similar races in Europe; while it is also 

 evident that some pre-historic skulls, supposed to be of vast 

 antiquity, as, for instance, that of Engis, bear a very close resem- 

 blance to those of the Algonquin and Iroquois Indians. 



ON THE RESPIRATORY SYSTEM OF INSECTS. 



By S. H. Parkes, Birmingham, England. 



The subject of the present paper is The Respiratory System 

 of Insects, and its direct relation to their nervous, nutritive and 

 muscular functions, and as I trust this will only be the first of a 

 series of papers on the structure of this remarkable and interesting 

 class in the animal kingdom, I may perhaps be permitted to make 

 a few introductory observations. 



To some minds the discussion of insect physiology may appear 

 a well nigh threadbare and exhausted subject, so much having 

 been said and written on the structure, habits,' and economy of 

 these creatures. But, like other branches in the great domain of 

 scientific research, this one has still hidden wonders, which will 

 repay the labour of diligent and persevering inquiry. 



No one ever thinks of asking, " What is a Bird ?" or "What 

 is a Fish V but the question has yet to be answered satisfactorily 

 and scientifically, " What is an Insect?" Nor need we wonder 

 at the difficulty which naturalists have felt, when striving to find 

 a distinctive name for these creatures ; for of all the living things 

 which this wondrous world presents to our view, there is no one 

 class which contains such a strange diversity as that usually 

 designated Insects. 



There are insects with wings, and without wings ; with jaws, 

 and without jaws ; with two eyes, and with many thousand eyes; 

 some as large as humming birds, and others so small that the aid 

 of a microscope is required to enable us to see them. Some 

 insects, with dainty appetite, sip honey from the nectaries of 

 flowers; while others, furnished with a pair of terrible jaws, grind 



