200 
Scutellaria Minor L. in Lunedale. 
FLIGHT IN INSECTS. 
W.H.P. 
Interest in the problems of flight has led Professor A. 
Magnan of the College de France, to study the problems of 
flight in insects (Actualites scientifiques et Industrielles , Nos, 
46 and 60). The study is being carried out with ultra -rapid 
cinematograph cameras which can take as many as 12,000 
views per second, a usual speed being 2-3,000 views per second. 
The principle of these cameras is that a number of films and 
lenses are used, the exposures of the films being synchronised 
so that the photographs are taken in known order. 
A large number of insects have been photographed in 
flight with this instrument, attention being paid particularly 
to hovering flight, where it is possible to calculate the work 
required to hold the weight of the insect against gravity and 
the work done by moving the wings. In order to estimate 
the latter, the area of the wings, the amplitude of their beats 
and the number of beats per second are measured. The 
highest number of wing beats recorded per second is 160 for 
Sarcophago carnaria and Musca domestica, with wing beats 
respectively of ioo° and 90° in amplitude. Most of the Diptera 
have over 100 beats per second, but Tipula gigantea has only 
48, and the beats only extend over 70°. Among Hymenoptera, 
Bombas muscorum does 128 beats per second, Vespa crabo 
only 53. The Lepidoptera are still slower, ranging from 48 
in Plusia gamma to 8 in Philosamia cynthia. Vanessa cardui 
is typical with 21 beats per second. Neuroptera are rather 
similar, 20 to 40 beats, and Ephemera vulgata, for example, 
has 29 beats per second. The Coleoptera range ‘somewhat 
higher, 33 in Lucanus cervus to 72 in Telephorus fuscus. 
SCUTELLARIA MINOR L, IN LUNEDALE. 
CHRIS. A. CHEETHAM. 
The Lesser Skullcap is an uncommon plant in Yorkshire and 
it has no station recorded in our Flora for the Lune drainage 
although it is noted in the West Lancashire Flora from the 
Arkholme and Whittington moors. On a recent visit to 
Keasden I found it in fair quantity and in nice flower. The 
date, July 17th, is a month earlier than we usually find the 
Marsh Gentian in flower at this place, but this year is an 
exceptionally early one for many species and the Marsh 
Gentian is one of these, for it was in nice flower. A moss, 
Campylopus atrovirens De Not., occurs in plenty on this 
moor ; in Yorkshire this species is usually found on older 
rocks of Silurian age but it is plentiful here where the rocks 
belong to the Millstone grit and shales of carboniferous age. 
The Naturalist 
