336 
Proceedings of the Royal Society 
On the Physiology of Wings : being an Analysis of the 
Movements by which Flight is produced in the Insect, Bat, 
and Bird. By James Bell Pettigrew, M.D., F.R.S. Com- 
municated by Professor Turner. 
(Abstract.) 
(Received 2d August 1870.) 
In the present memoir the author enters very fully into the 
figure-of-8 wave movements , described by the wing in space, to which 
he first directed attention in March 1867.* He has adduced the 
experiments with natural and artificial wings, on which his descrip- 
tion was originally based, and has shown, by the aid of original 
models and a large number of diagrams and drawings, that artificial 
wings can be made to approach indefinitely near to natural ones , 
not only in their structure, hut also in their movements. He 
further points out that the fins and tail of the fish — the flippers 
and caudal extremity of the whale, dugong, manatee, and porpoise, 
and the flippers of the seal, sea bear, walrus, and turtle — hear a 
close analogy to wings, and ought to be studied in connection with 
them. As further proof that the wing describes a figure-of-8 wave- 
track in flight, the author cites the results announced in February 
1869 by Professor J. B. Marey, of Paris.f 
* Vide “ The Various Modes of Flight in Relation to Aeronautics ; ” by the 
Author in the “ Proceedings of the Royal Institution of Great Britain for 
March 22, 1867 ; ” also his memoir “ On the Mechanical Appliances by which 
Flight is attained in the Animal Kingdom,” read to the Linnean Society of 
London on the 6th and 20th of June 1867, and published in extenso in the 
26th volume of their Transactions, a large number of woodcuts and engrav- 
ings being specially devoted to the elucidation of the figure-of-8 wave track 
made by the wing as observed in the flight of the insect, bat, and bird. 
t “ Revue des Cours Scientifiques de la France et de l’Etranger.” Professor 
Marey, in a letter addressed to the French Academy, under date May 16, 1870, 
fully acknowledges the author’s claim to priority (as regards himself) in the 
discovery of the figure-of-8 wave movements made by the wing in flying. M. Marey, 
in the letter referred to, states (“ Comptes Rendus,” page 1093, May 16, 
1870), “ J’ai constate qu’ effectivement M. Pettigrew a vu avant moi, et 
represente dans son Memoire, la forme en 8 du parcours d© l’aile de l’insecte: 
que la methode optique a laquelle j’avais recours est a peu pres identique a 
la sienne je m’ empresse de satisfaire a cette demande legitime, 
et je laisse entierement la priorite sur moi, a M. Pettigrew relativement a la 
question ainsi restreinte,” 
