NATURAL HISTORY NOTES 247 
Fox showed the greatest joy, barking loudly and leaping up and down, while we 
clapped our hands. It seemed very remarkable to me. 
Could this show in the dog’s brain a capacity for receiving the influence of a 
psychical impression transmitted by the intensity of our wills, of which we were 
unconscious ? 
“ Tregethew ," St . Martin, R.S.O. Harriet E. Olive. 
S. Coniwall, November lo, 1904. 
196 . Black Squirrel. — A neighbour reports to me a black squirrel in one 
of his coverts. I do not remember having come across a case of melanism in this 
British rodent, though light coloured ones are not uncommon. 
Edmund Thos. Daubeny. 
197. Black-headed Mannikin. I have at last ascertained that the 
strange finch shot here four years ago is the Black-headed Manniiiin {M. 
atricapilla). It is a native of India and Burma. The one killed here must have 
escaped from captivity. 
Edmund Thos. Daubeny. 
198. Swallows. — The swallows took their departure this year from my 
immediate neighbourhood at a very early date. On September 27 I noticed a 
considerable flock of chimney-swallows and house-martins circling about opposite 
this house, but more were to be seen the following day. On October 3 a few 
of both species appeared near the house, but since that date not a solitary 
straggler has been noticed. Perhaps the rather severe frosts which prevailed at 
the end of September may have sent the pretty creatures away earlier than is 
usually the case. 
Fyfield, near Abingdon. W. II. WARNER. 
199. Goat Caterpillar. — Mr. Lowther’s Goat Caterpillar (p. 236) did not 
actually eat the cardboard, but merely cut a hole in it and used its jaws in 
endeavouring to escape. It would have treated a wooden box, or even a leaden 
one, in much the same way. These caterpillars do not leave the tree in which 
they have lived till they are full fed and have ceased to take food. They desert 
the tree in the autumn and pupate at a distance. Next thing they turn into a 
moth. I always put them in a tin canister and supply them with shavings, which 
they cut up in forming their cocoon. 
Edmund Thos. Daubeny. 
200. Tapping. — Your valuable correspondent, Mr. E. T. Daubeny refers 
to “tapping” sounds that occasionally are heard in rooms of our houses similar 
to the noise of the “death-watch.” May I be allowed to state what has forcibly 
struck me as the cause of this sort of noises. 
I cannot help feeling convinced that these sounds are emitted from wooden 
furniture. I have generally noticed that I heard them after a sudden change in 
the temperature from heat to cold. I have also noticed that similar sounds may 
be produced at pleasure with a stove that has a fire-brick back to it. After a 
fierce fire has thoroughly heated the fire-brick back, suddenly with a shovel pull 
the burning coals forward from the back, and as the back cools, you will dis- 
tinctly hear these noises emitted. 
In furniture, heat causes it to expand and open the interstices of the wood, 
which become filled with air. .A sudden cooling, on the other hand, causes the 
wood to contract, and the interstices then close and forcibly expel the air with 
these explosive sounds. The noises vary in force according to the quantity of air 
expelled and the smallness of the opening through which it is expelled, but they 
are always similar in sound, though sometimes the air is expelled quicker than at 
other times. 
When the lives of invalids are “ hanging by a thread,” a sudden change to 
colder weather often causes death. This is the reason why the death of invalids, 
especially in the olden times when they had fewer comforts, has been frequently 
noticed to occur after these noises, aad the sounds have consequently got the 
name of the “death-watch.” I can hardly think it possible that these noises 
can be caused by a very tiny insect that is sometimes found in old furniture. 
Hampstead, Peter Hastie. 
November 14, 1904. 
