value of Insect Collections. 491 
of British insects, averaging twenty to a species, and 
thus consisting of 240,000 specimens, could, I think, be 
made for £6000, the average cost per specimen being 
6d. It will be perhaps objected that I have allowed 
nothing for the cost of travelling, which must, of course, 
be incurred; but a little reflection will show that this 
would be very small under the conditions I am sup- 
posing, and would be more than recouped by the sale of 
duplicates. 
The next point for consideration is the extent to which 
the preceding calculations must be modified in con- 
sidering the cost of an ultra-British,—that is to say, a 
general,—collection. 
At first sight it would appear that to make, in England, 
a collection of extra-British insects must be more, ex- 
pensive than making one limited to the indigenous 
creatures. And doubtless it would be, if all the depart- 
ments of the work were undertaken by one man, as I 
have supposed to be the case in the formation of a 
British collection. 
The efforts of one man in forming a general collection 
of the insects of the world would, however, be thrown 
away, and for this larger purpose the combination of a 
number of employés would be essential; and in that 
case the advantages derived from division and organisa- 
tion of labour would more than compensate for the fact 
that some of the operations have to be carried on in 
distant parts of the world. We will, however, suppose 
‘that only similar progress should be expected for like 
expenditure, and then multiplying our factors by twenty 
we arrive at the result that for an annual expenditure of 
£3000 a general collection of insects progressing over 
a long series of years at the rate of 6000 species and 
120,000 specimens of selected insects could be collected, 
mounted, arranged, and preserved. 
This estimate of the rate of progress that might be 
made is a very moderate one, as can readily be ascer- 
tained by checking it in the converse manner of arranging 
a staff, calculating the cost and the results that it could 
attain. It is then seen that the above sum is sufficient 
for attaining the result mentioned. 
Cost and value are very different things, so that when 
we come to consider the value of collections we have to 
take a wider view than we have done when considering 
