780 
Annual Report for 1894 of the Zoologist. 
suggestions which have from time to time been brought forward. As 
this leaflet is probably in the hands of all those interested in the 
growth of mustard, it is unnecessary to repeat here the substance of 
numerous previous reports, and I shall confine my observations to 
certain modifications of treatment which many visits to infested dis- 
tricts and much conversation with mustard growers have suggested 
to me. 
It is very doubtful whether the plan, sometimes advocated, of 
burning damp .straw, or filling trenches with tar, to arrest the march 
of the beetle, is of any real utility, as the beetles readily travel over 
very much greater obstacles. Nor does the method of using dress- 
ings, other than forcing manures, seem to be justified by results. 
It would be well to tar the fences in the early spring, for the 
double purpose of preserving the timber and of destroying the 
beetles, which are hibernating in the chinks and crannies of the wood. 
A suggestion which seems to be worthy of more attention than 
it has hitherto received is the deliberate stocking of the mustard 
field with chickens or ducklings. 
The fowls selected should be of the most active breed procurable, 
and free from feathers on the legs. It will probably be necessary to 
purchase in the ordinary market ; but if such active fowls as Leg- 
horns, or the cross between Plymouth Rock and Dorking, can be 
obtained, so much the better. The birds should be quite young, 
about the size of starlings, and should be stocked at the rate of 
about twelve to the acre, as soon as the mustard plant appears. 
They must be furnished with waterproof houses with raised 
wooden floors, each house to shelter about twenty -five chickens. 
At first they must be fed twice a day ; but when insects become 
more numerous the morning feed must be discontinued, but a full 
meal given in the evening. 
Common chickens suitable for the purpose will probably cost 
about sevenpence, and will fetch two shillings in the autumn, 
having in the meantime freed the crop from various insect pests. 
Young ducklings are, perhaps, even more satisfactory, as they are 
better able to pick the larvae off the under side of the leaves. 
The ingenious beetle-catching machine devised by Mr. Cole 
Ambrose, of which I have examined a model, seems well cal- 
culated to destroy great numbers of the various mustard beetles in 
case of a bad attack. Its cost may prevent the smaller growers 
from availing themselves of its services, uidess they overcome the 
customary reluctance to combine in purchasing one. It seems 
worth while considering whether some less costly adaptation of the 
same principle could not be devised for fixing to the framework of 
some implement, such as a horse-hoe, already possessed by the 
farmers, though in this case the somewhat low axle would prevent 
its use, except in the earlier stages of the crop. 
I am greatly indebted to Messrs. James and Samuel Egar, of 
Thorney, near Peterborough, for advice with regard to this pest. 
