oD CORN AND GRASS. 
seriously injurious presence extended. To these are added some con- 
siderations of the geological nature and characteristics (as of soil, 
neighbourhood of coast, &c.) of the land affected, the nature of 
pasture-land attacked, and details of the migration of the caterpillars, 
when their ravage was complete in one place, to other grasses or crops, 
as to Oats, in a lesser degree to Barley, and occasionally to Rye. 
Prof. Odo Reuter’s paper, which extends to ten pages, with a good 
map showing localities and degrees of attack, appears to me of rare 
value, as giving what is so seldom obtainable—information from a 
skilled and reliable source of the first appearance of a bad crop-pest in 
a great country, with data year by year of its injurious spread until it 
has made good its foot-hold. It gives much for consideration, and I 
beg to offer my best thanks to Dr. Enzio Reuter, Consulting Ento- 
mologist, of Helsingfors, for presenting me with a copy of his brother's 
work. 
The chief remedial measure which has been practised in this 
country is firing the pastures, and thus destroying the heath and 
mountain plants together with the grass, and in this way getting rid 
of the caterpillars sheltered amongst them. In the very bad attack of 
these caterpillars to mountain ground in Glamorganshire in 1884, the 
smoke of the mountain fires was especially mentioned as showing the 
large area and the severity of the infestation requiring such measures 
to check it. 
But besides the direct destruction of the pests by fire, there is the 
important consideration that the caterpillars have been found to have 
an intense dislike to the burnt surfaces, and will move away with great 
rapidity when in their migrations they come on burnt land. Thus it 
would appear a band of fired ground might be used as a protection 
where the migrating bodies are moving to more valuable crops, and 
also in directing their course towards any neighbouring stream or pool, 
or peat-hole, which even in natural circumstances the caterpillars on 
the march will fall into in such extraordinary numbers as to make 
it appear that whether wet or dry they continue their course right 
onward. 
In my reports of 1884 it was noted that at Treorky Station (on the 
Rhondda branch of the Cardiff and Merthyr Railway) the mountain 
brook running from the Fforch Mountains was thick with myriads of 
these caterpillars, which had been drowned by falling into it during 
their march across the side of the mountain.* 
In 1894 Mr. Service reported that a party fishing for five or six 
miles down the river Ken, in Kirkcudbrightshire, found all the trout 
they caught perfectly crammed with these caterpillars. 
Their determination in their onward march may certainly be well 
* See my ‘ Eighth Annual Report on Injurious Insects.’—Ep. 
Jy Pp 
