429, Mr. D. Sharp on the cost and 
their cost. We may, however, dismiss the question of 
the value of entomological collections to individuals 
with a very few words, because each individual is the 
best judge of the value he himself puts on a collection. 
We know that collections of insects never pay in money 
those who have formed them for the labour and time 
they have bestowed on the work; and I do not suppose 
any private person ever undertakes the formation of a 
collection for himself with the expectation of recouping 
a sum of money as an equivalent for his time and labour. 
Any one who did so would probably be disappointed. 
But there are reasons why a public collection has, or 
rather should have, a much greater value relative to its 
cost than is the case with private collections. These are 
—1. The fact that a public collection continues to exist 
for a great number of years, and, if intelligently formed 
and properly arranged, would acquire a constantly in- 
creasing value from its historical associations, and from 
the extinction in nature of the species contained in it. 
2. The fact that a public collection receives great incre- 
ments from private individuals, without anything like a 
corresponding expenditure on its part. 3. That the 
educational and hedonic results of a collection are, or 
should be, in the case of a public one, extended over a 
greater number of individuals without any corresponding 
increase in its cost. 
These considerations not only amply justify the forma- 
tion of public collections, but also render it certain that 
it is worth while the work should be well done; indeed, 
the considerations render it very evident that the value 
of the collections depends almost entirely on their being 
undertaken and carried on in an efficient manner. 
It may not be superfluous to deal with these reasons 
at somewhat greater length. When we recollect that a 
large copper butterfly was worth a few years ago about 
a shilling, and at the present time about six pounds, and 
that the chain of causes that have led to this increase of 
value are at work in the case of a large number of other 
insects, we recognise that the increment of value from 
this source is far from unimportant. If the spread of 
the white races over the globe continue to go on as 
rapidly as it has done, it is certain that there will be a 
great increase in the value of very many specimens that 
can now be procured for a very small expenditure. 
