VACATION RAMBLES 255 



whole year the growth of the crop on which it subsists. 

 There are not many injurious insects which are absolutely 

 restricted to one food-plant, but there appear to be some. 

 The difficulty which I foresee in extirpating a single species 

 of noxious insects makes me very indifferent to a project 

 for the extirpation of insects in general throughout the 

 world. We shall have plenty of time to weigh the con- 

 sequences before it becomes a matter of practical business. 



XLVI. VACATION RAMBLES. 



The expansion of our towns and cities is ruining much 

 that the naturalist loves. London has devoured many 

 a pleasant wood and field. A little more than a hundred 

 years ago Queen Square, hard by Southampton Row, 

 was thought to be a delightful abode, because it com- 

 manded an unbroken view of Hampstead and Highgate. 

 The naturalists of the first half of the nineteenth century 

 looked upon Leystonstone, Tottenham. Highgate, Sydenham 

 and Blackheath as unspoilt country, where nature could 

 be explored without hindrance. Our busy provincial 

 towns grow with almost equal rapidity. I know of a 

 little valley near Leeds, where in my own boyhood rare 

 marsh-plants and curious insects were to be found in 

 undisturbed profusion. That valley is now crowded with 

 forges, dyeworks, and back-to-back houses. Near Sunder- 

 land was once a delightful dene, where a bright stream 

 flowed into rock-pools, which filled with sea-water at 

 every tide. A singular mixture of marine and freshwater 

 animals used to people these pools, but when I was taken 

 to see them by their discoverer, great ironworks smothered 

 the place with ashes and smoke. One could relate such 

 experiences at wearisome length, and to the naturalist, 

 as to some few others, these changes are pure loss. He 

 cares little for " unexampled prosperity " and " increase 

 of rateable value." The beauty and wholesomeness of 



