] 60 An Ornithological Letter from Mentone. 
it, as Prof. Savi, in his 1 Ornitologia Toscana/ mentions it as 
a bird of rare occurrence there. 
Within a quarter of an hour’s walk from our house is the 
frontier-bridge of Pont St. Louis. One might, from the name, 
expect to find a river flowing under the arch, and forming the 
actual line of demarcation, or at least the stony bed where a 
river might at times be supposed to flow ; but no; precipitous 
rocks, forming the sides of a fine gorge, are the real defences, 
and the bridge is simply the means of bringing the cornice road 
across its rugged mouth at the height of about 100 feet. Here 
rock-loving birds find every requisitefor their varied needs. The 
Wall-creeper {Tichodromaphcenicoptera) enjoys the perpendicular 
faces of rock in the crannies of which abound the spiders and 
larvse which it loves to probe after with its long bill. The Rock- 
Martin ( Hirundo rupestris ) sweeps gracefully around the shel¬ 
tered bays, where, in the coldest weather, it may find gnats and 
other ephemera. The Blue Rock-Thrush ( Petrocincla cyanea ) 
seeks the lonely points of inaccessible pillars of rock from which 
he can guard warily against surprise; and the Black Redstart 
(Ruticilla tithys) leads a merry life among the loose drifts of 
stones and the briary tangles of the lower hollows. The Rock- 
creeper (Tichodroma phcenicoptera) , with the crimson-aud-white 
spotted wing, is fortunately a bird specially exposed to the scru¬ 
tiny of the observer, his love of exposed surfaces of rock, and his 
antipathy to long flights, allowing us even hours of undisturbed 
examination. When seen flying, the impression conveyed us is 
of a bat rather than a bird, the stroke of its wing being spas¬ 
modic and laborious; for this reason it soon approaches the 
rocks, to which it applies itself as a fly might to the wall of a 
room, and working up the surface by means of vertical jumps 
(the wing being scarcely unfolded), in that way traverses spaces 
of from 10 to 14 inches. It was not until I had a specimen in 
my hand that I could understand how a body starting parallel 
with the rock could be propelled upwards, contrary to the laws 
of gravity. The apparatus is indeed remarkable, consisting of 
the following:—a short strong tarsus; three toes directed forward, 
having claws hooked for grappling—the central of these three 
measuring y^ths of an inch, including its curved nail; and lastly. 
