Redi* s Experiments on the Generation <yf Insects. 221 



be found. It is to be hoped, that the public will be favoured 

 with a new edition of that excellent work, which contains 

 much practical information, but has been out of print seve- 

 ral years. The correct work of Selby may be thought 

 to supersede it, but as that does not give the dimensions, 

 the size of a bird cannot be ascertained without his Il- 

 lustrations, which are much too expensive to be generally 

 obtained, and a dictionary of the provincial names is highly 

 desirable. From the foregoing list, it appears we have 

 seventeen species of falcons, and, I believe, no more, though 

 others have been placed in our Fauna, such as the Spotted 

 Falcon and Grey Falcon of the Brit, ZooL, which I have 

 but little doubt are not distinct species; the latter being 

 no other than a Gerfalcon, and the former a Gerfalcon 

 or variety of the Common Buzzard, though Montagu, in 

 his Supplement, seems to think the Spotted Falcon a dis- 

 tinct species. The great confusion among the falcons has 

 arisen chiefly from the difference of plumage, which exists 

 between the adults and young of several species, and from the 

 various changes which they undergo in arriving at maturity ; 

 the complete dress not being attained in some till the fourth 

 or fifth year, and even later. The term noble appears to me 

 to have been applied, not to all such as take their prey in the 

 air, which is the definition given by your correspondent Z. B., 

 and who, in that case, I think, improperly excludes the eagles, 

 which, according to Temminck and Montagu (see Montagu's 

 Supplement, article Eagle, Ring-tail), pounce their prey on 

 the wing, but to have been used to denote such as were used 

 in falconry only, which was formerly the sport only of princes 

 and noble persons, 



London, May, 1828. . T. F. 



Art. V Some Account of Francesco Redi's Experiments on the 

 Generation of Insects. ByT. L. H. 



Sir, 

 It is, I believe, well known, that, till the time of Redi (died 

 in 1697, aged 70), equivocal generation was the subject of 

 general belief. This celebrated Italian physician was the first 

 to prove, by that infallible test, experiment, that insects were 

 not engendered in putridity. The work in which he recounts 

 his labours to do this, is in the form of a letter to the Signor 

 Carlo Dati, and consists of a hundred and fourteen close 

 octavo pages. It is true that in this space there is much 



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