NATURAL HISTORY NOTES 
1 37 
think that lichens would be the best plants for the purpose, and preferably 
arboreal lichens, though wall lichens and ground lichens might also be noted. 
My object in fixing on lichens is three-fold : (i) I believe them to be highly sus- 
ceptible to smoke. [Their place near London is usually taken by the bright 
green slime, Protococcus viridis .] (2) The presence or absence of tree lichens is 
very readily determined. (3) The distribution of lichens is not affected by the 
raids of destroying trippers in the way that ferns and many other plants are. 
Obviously, other plants might be chosen, and surveys for each might be concluded 
in the course of the same expedition. The bicycle would be indispensable. 
Twitchen , Alorthoe, G. B. Longstaff. 
R.S.O., Devon. 
May 4, 1903. 
Double Lady’s Smock. — In two localities near here, at Ilythe and on the 
road to Hursley (where Keble lived), I have found the double variety of ladies’ 
smock, Cardamine pratensis. This year it is very vigorous and remarkably 
proliferous. 
9, Cavendish Grove, The Avenue, Southampton. H. John Beeston. 
May 10, 1903. 
Fox Moth.— Many years ago I lived near the late Mr. Wm. Buckler, whose 
drawings of Lepidoptera in their different stages have never been excelled, and 
hardly ever equalled. We often used to meet. One day, in speaking of the fox 
moth (Lasiocampa rubi), he told me of the difficulty there was in rearing it. Full- 
fed caterpillars are easily obtained on any heath in the autumn ; and the usual 
plan was to imprison them with some leaves and dry earth in a box for the winter, 
when nothing more was needed till they turned to moths. But the caterpillars 
always died in a mysterious manner during hybernation, only 3 or 4 per cent, 
coming out, and most of these with shrivelled wings. Armed with these facts, I 
determined to try a different plan, and to copy Nature’s method as closely as 
possible. On the slope of my lawn I placed a square hand-glass, used for raising 
seeds, which I let into the turf about two inches, carefully stopping all egress by 
pressing down the ground inside and out ; and put within some full-fed fox-moth 
caterpillars. In a short time they hid up for the winter. Their arrangements 
were of the simplest kind. They merely cleared a space at the root of the 
grass rather less than the size of half a-crown, in which they curled up, the 
long hairs of their body alone preventing actual contact with the bare earth. 
Next spring they appeared again for a short time and basked in the sun, refusing 
all food. They then returned once more, spun a loose almond-shaped cocoon 
about the beginning of May ; nearly all appeared as perfect insects. The secret 
was this: The juices in the bodies of those in the boxes became exhausted from 
their being kept too dry. Mine did not lose weight from lying close to mother 
earth. 
May, 1903. Edmund Thos. Daubeny. 
Oysters and Typhoid. — I lived for nineteen years at the head of Lang- 
stone Harbour, near Emsworth, whose oyster beds are reported to have been the 
cause of much typhoid and death, and have spent many an hour, day and night, 
among the mud banks there, which when the tide is down are not covered with 
water. Marine plants of different kinds grow luxuriantly on the mud, which in 
places is very deep and treacherous. In hot weather this vegetable matter lies 
sweltering in the sun, and when it decays gives off an offensive odour like an 
open drain. I have known many severe cases of gastric trouble caused by eating 
mussels taken in the waters of these harbours. The fishermen looked on them as 
poisonous, though mussels from the open sea are less harmful and often eaten 
with impunity. May not the germs of typhoid exist not only in the sewage 
flowing over the oyster beds, but also be lurking in every square yard of mud, 
unless it is always under water and in a tideway ? 
Edmund Thos. Daubeny. 
Polar Thunder — In reading Harriet Martineau’s “ Feats on the Fiord ” 
the other day, I came across the following footnote: — 
“ Erica knew thunder only by report, as there is none so far north as the 
part of Nordland where she lived. Thunder ceases at 66 degrees of latitude.” 
