466 IV. EXPLANATIONS OF THE 
some of these latter having been seen once or oftener, but being 
found here no longer. Echinophora spinosa may be one example 
ofan extinct casual. Others appeared on or near the sites of the 
Exhibitions of 1851 and 1862, and lingered there a brief time; 
long enough, unfortunately, to encumber our book lists with 
names which it would have been more convenient, if not also more 
sensible, never to have admitted into them. It is to be regretted 
that more reticence is not practised by our juvenile botanists, so 
hurriedly anxious to make book records of such valueless facts. 
If all of us freely indulged in that practice, our list of casuals 
would soon be made longer than the list of all others put together. 
Almost anything in cultivation for use or ornament, outside 
hothouses, could be made into an occasionally-wild plant, through 
an industrious examination of the rubbish-heaps of gardeners and 
farmers. The refuse from oil and flour mills, dock sides where 
ship rubbish is thrown, and such like chances, might equally 
reward an equally useless industry. 
One warm autumn, I met with a luxuriant plant of the Tomato, 
bearing ripe fruit, on a bit of waste space near the bridge over 
the Thames at Walton. But I did not make haste to record that 
grand discovery in a Journal of Botany, and to declare Lyco- 
persicum esculentum ‘perfectly established” by the Thames in 
Surrey. I knew that the spot had been often used for throwing 
down waste refuse from a neighbouring house aud garden; and 
as might readily have been expected, no descendants of my Tomato 
were to be seen there the two autumns following. In the same 
neighbourhood, I once saw the blue Nemophila quite abundant 
in a corn field; and repeatedly I have seen stray examples of the 
same favourite garden annual, in fields and on rubbish heaps. 
But I am guiltless of making a formal record of it as a 
“naturalised plant,” and arguing for “the propriety of including 
it in the British Floras” for ever thereafter. Itis to be hoped 
that the mention of the two plants here will not be pounced upon 
as an excuse for adding them to the list of Surrey plants, to be 
printed in any future Flora of the county. Not that I can myself 
be held wholly innocent of book records for merely casual aliens; 
