THE RECURRENT LARYNGEAL NERVE. 661 
question is not only entitled to respect, but must bear very great 
weight. The species possessing the longest range c Ff vision with 
which I am acquainted are the beautiful Afftus volans, Camb., and 
A, splendidus, Rainb. These spiders detected prey at a distance 
of 7 inches. The instant one of them saw an insect in the box 
in which it was imprisoned, it sprang upon it with unerring 
precision, proving not only that it saw it, but also that it had 
accurately gauged the distance. With other species with which I 
experimented, such as Hrgane scutulata, L. Koch, the distance at 
which they detected prey was less, ranging from 5 to 3 inches. 
Whenever a fly was introduced, if the imprisoned spider was 
resting in a corner, it instantly displayed signs of activity and 
keeness of vision, for which ever way the fly moved, the Attid 
would follow its course by moving its cephalothorax either to the 
right or left, so as to keep its prey in view ; when the fly stopped, 
the spider would commence to draw upon it with a slow, stealthy 
movement ; if it moved, then the pace would be quickened, and 
so on until it had, unperceived by the fly, arrived within leaping 
distance, when the final spring was made. 
CONCLUSION, 
From a study of the foregoing evidence, therefore (leaving out 
of the question the experiments upon the Laterigrada, which were 
not sufticient to be conclusive) | am compelled to support the 
decisions arrived at by Simon, McCook, and Dr. and Mrs. Peck- 
ham, that the Citigrade and Attidw are each endowed with long 
range of vision, and that this is the only theory that can be safely 
advanced in explanation of their habits either in the field, or in 
confinement. 
No. 3.—TRANSPLANTATION OF THE RECURRENT 
LARYNGEAL NERVE. 
By T. F. Macponap, M.B., C.M. 
(Read Tuesday, January 11, 1898. ) 
To appreciate the idea underlying the above experiment, the 
peculiar anatomical relations of the recurrent must be kept in mind. 
The nerve is a branch of the vagus given off in the thorax ; on the 
left side it dips round the arch of the aorta, and runs back from 
thence to supply the crico-arytenoid muscle of the larnyx. This 
disposition of the left nerve round the aorta renders it peculiarly 
liable to injury as seen in cases of aneurism of the arch of that 
