71 
Before closing my few remarks about the locusts, it may interest 
you to know that for some time past I have been trying to find 
time for the preparation of an illustrated treatise on this important 
subject. Owing to pressure of work, however, I have not yet 
been able to get it ready. The coloured plates are ready, speci- 
mens of which are here to-day for your inspection; and in this 
connexion I may be allowed to point out some of the difficulties 
under which one labours when preparing books of this kind. 
The notes are got ready, and you place them before you on your 
table, when lo! a knock is heard, and a visitor is announced ; 
or else you are besieged with letters asking for information on 
matters all and sundry. I would here like to commend to my 
youthful hearers the excellent practice of replying to all letters, 
if at all possible, on the same day as that on which they are 
received. I mention this as some of you may at a future time 
hold a similar position to that held by our experts at the present 
time. If you are at literary work correspondence should not, if 
possible, be allowed to accumulate. It is a bad practice, as a 
grower when he writes for your advice is no doubt anxiously 
awaiting the reply to his request for information. Reply at once. 
The matter is then off your mind, and you are ready for the next 
day and the work required of you. 
In the early part of last year I received several caterpillars of 
the “Celery Vine Moth” (Cherocampa celerio). In some in- 
stances they were described to me as “ horrid things with horns 
on.their heads” (the so-called horn is fixed at the other end), and 
that when handled they ‘“‘ would ‘spit’ and fly back.” I was 
anxious, of course, to interview this “monster,” when to my 
astonishment it proved to be the larva of the beautiful Hawk 
moth, which you will find figured in Plate XIX., page 108, of 
Part II. of my new book on insect pests, an advance copy of which 
I have obtained to show you this afternoon. If these persons had 
taken the trouble to place one of these caterpillars in a box and 
fed it with freshly gathered vine leaves, they would have been 
able to trace the insect from the grub to the pupa, and from thence 
to the perfect insect. This would have been very little trouble, 
and from that time they would have had a practical acquaintance 
with the habits and life-history of one of the worst caterpillar 
pests of the vine. ' 
How often has it happened that a traveller who, by stress of 
weather or from other causes, has had to refrain from accomplish- 
ing that for which he had left home, and has had to pass many a 
weary hour at some country hotel, and who has had a bitter experi- 
ence, that is, if he be an intellectual person, in walking about 
doing nothing? Whereas had he been a naturalist his spare time 
could have been agreeably and profitably spent in observing and 
collecting some of the insects or plants of the district. As to 
