^08 Scientific Intelligence, 
are laid upon the grass, alFords a demonstrative proof of their 
singular habit. The circles they form, though not of exact 
symmetry, are sufficiently so to excite notice ; their diameters 
vary much, this probably depends upon the number of birds in 
a flock. The birds make the same twittering whistle when 
upon the ground, as when perched in trees or on reeds, When 
I have noticed them, they have generally alighted in pastures ; 
some few times I have seen them in stubble-fields, but never 
upon fallow or new ploughed land. For what purpose Provi- 
dence has endowed these creatures with so peculiar a habit, I 
am at a loss to imagine. I have sometimes thought, that the 
circles of a deep green colour, which we occasionally see in 
pastures, and which are known by the name of Fairy Rings,” 
might owe their origin to the fertilizing quality of the decom- 
posed faeces of these birds *. This, however, is only conjecture. 
I mention it merely, that others interested in such pursuits, 
may make observations on the subject, which, when opportu- 
nity again offers, I intend dmng .”- — Letter from Mr John^on^ 
HiU Top^ Wetherhy, October 1820. 
25. Notice of a prolific cross-breed between the common Cat 
and the Pine-Martin^ (Mustela Maries ). — We find by the Bi- 
hliotheque Universelle^ that there has been lately presented to 
the Imperial Society of Natural History of Moscow, an animal 
which appears to be a cross-breed, formed by the meeting of the 
common cat and the pine-martin, and the fur of which pro- 
mises to be f. valuable article of commerce. The specimen pre- 
sented to the Society was sent from the Government of Penza, 
where the pine-martin is very abundant. The following his- 
tory is given of the cross-breed. — A domestic cat disappeared 
from a house in Penza, and returned in some days in a state of 
impregnation. At the usual period the cat littered four young 
ones, two of which very much resembled the martin. Their 
claws were not retractile, as in the cat, and the snout was elon- 
gated like that of the martin. The two others, of the same lit- 
ter, more nearij resembled the cat, as they had retractile claws 
and a round head. All of them had the black feet, tail, and 
* I am aware that philosophers attribute “ Fairy Rings” to the agency of at- 
mospheric electricity, &c. | but this seems to be no more than hypothesis. 
I 
