172 ON MAKING USEFUL 



piidibunda, or Pale Tussock Moth, is called the Hop-Dog in the 

 hop-growing districts ; but for it to abound on fruit-trees in Bath 

 was quite a new thing to me. A description which he gave me 

 failed entirely to enable me to discover what the insect really was 

 which he called the Hop-Dog, but I suspected it was not the larva 

 of the Tussock Moth. Fortunately, it was possible for me to go 

 to the garden and see the insect, when it turned out to be the 

 larva of Orgyia antiqua^ or the Vapourer Moth, which is very 

 common everywhere, even in the metropolis. He, however, 

 thought it was the Hop Dog, and that the wind had blown the 

 eggs or the insects over from the hop-gardens of Kent ! Now, 

 suppose for a moment that he had published his own account 

 either in a scientific or a local paper, how difficult, if not impos- 

 sible, it would have been, in after years, to have discovered the 

 real facts of the case ! 



I need not point out what a very superior and correct view of an 

 insect is obtained when it is seen under a good binocular micro- 

 scope, compared with that which it is possible to get by the use of 

 the pocket-lens ; but from the manner in which our cabinets are 

 usually arranged, the specimens are not readily available to place 

 under the microscope. They have to be removed from the cabi- 

 net, and, after examination, again replaced, this removal being in 

 itself attended with some considerable risk, and consequently it is 

 not likely to be often done. I was once shown a type collection 

 of small beetles that had been arranged by a foreign professor. 

 They were painfully exact and uniform. Each specimen was pre- 

 cisely the same height ; the pins were placed perfectly upright and 

 in straight rows. It was much admired by the gentleman who 

 owned it for its supreme neatness and regularity ; but he would 

 not on any account allow a specimen to be touched because he 

 was afraid he should not be able to replace it with the same regu- 

 larity as before ; hence the collection was useless, although the 

 specimens were intended as types to determine doubtful species. 

 I do not wish it to be understood that I advocate a slovenly 

 arrangement of badly-set insects; on the contrary, I think the 

 objects are so beautiful and interesting that a collection of them 

 ought to be as neat and attractive in appearance as it is possible to 

 make it. Nevertheless, I maintain that it may be laid down as an 



