66 THE ENTOMOLOGIST. 
opinions, the learned authors cite the wondrous discoveries 
of Carus, which seem opposed to them, and finally arrive at 
this solution :— 
“The endeavours of M. Carus to discover any proofs of 
a circulation in their last state, except in the wings at their 
first development, were without success. He observes that 
the fact of the currents of fluids in larve, not being defined 
by vascular parietes, enable us to comprehend the rapidity 
and facility with which the traces of the circulation are lost 
in the perfect insect. On the other hand, the existence of a 
circulation at one period, and its cessation at another, 
elucidates many circumstances connected with the physiology 
of these animals; for instance, the contrast between the rapid 
growth and transformation of the larve, and the stationary 
existence of the imago, &c. Lastly, he remarks that the 
phenomena of this circulation do not throw any light on the 
obscure subject of the mode of nutrition in perfect insects ; 
which, therefore, must still be supposed to be effected 
according to the idea of Cuvier,—without the intervention 
of vessels.”—‘ Introduction to Entomology, vol. iv. p. 96. 
To Dr. Bowerbank we are indebted for clearing up the 
doubts about circulation. He attributes the errors, for such they 
assuredly are, into which Lyonet and other great authorities 
have fallen, neither to haste, nor inattention, nor inability, but 
solely to the imperfection of the microscopes they employed. 
After the publication of his paper in the fourth volume of 
the ‘ Entomological Magazine, troops of scientific men came 
to test, and of course ended in verifying, his observation: 
Professor Owen, Marshall Hall, Newport, Gulliver, Mantel, 
Geoffroi St. Hilaire. Of the last-named the following 
reminiscence will be read with pleasure :— 
“One of the most remarkable of my visitors was the great 
French naturalist Geoffroi St. Hilaire, who paid a short visit 
to England in 1833. He had read my paper ‘On the Circu- 
lation of the Blood in the Larva of Ephemera marginata,’ and 
doubted the possibility of seeing the valvular action of the 
great dorsal vessel described therein. I had fortunately in 
my possession some very favourable subjects for exhibiting 
these beautiful phenomena; and when all was in order, and 
the great man applied his eye to the instrument, he-at once 
saw the very facts he had doubted, and, without moving his 
es a 
by 
