14 
NOTES OF OBSERVATIONS 
but not as causing much damage. Mr. Dobson mentions the grubs of 
the Celery fly as doing much damage at New Malden, Surrey, about 
September 28tli. On October 15th he notices them as still extremely 
numerous, and much more so than last year, for then some plots 
escaped; this season the celery in the same ground has been wholly 
destroyed. At Sedbury, West Gloucestershire, it is mentioned as in 
greater quantity than it had ever been seen before; and in various 
localities at Islewortli the crop was much injured; but on November 
7tli I noticed a patch of Celery that was remarkably healthy and little 
injured by the Fly in a garden on Hounslow Heath, not in the 
immediate vicinity of other Celery plants; this was on peat soil, 
shown in section to be about a foot and a half thick, over-lying three 
feet of gravel; possibly the gravel went much deeper, but the section 
was only about five feet deep. The commonly suggested remedy of 
pinching the grub in the blistered leaf, or removing the infested piece, 
does not seem to answer excepting when the attack is slight; and as 
the maggot is sheltered inside the leaf the only preventive appears to 
be making the leaves distasteful for oviposition to the Flies, or 
poisonous to the newly-liatched maggots. Mr. Herbert Grace mentions 
that he has found a solution of washing-soda, liberally applied to the 
plants, very effectual in destroying these pests. 
9. Psila Rosae. Carrot Fly. The Worm (Scottice). With regard 
to this Fly Mr. Donald mentions that at Balfour Castle, Kirkwall, the 
ground is of a strong clayey nature, and many experiments have been 
tried in previous years to grow good Carrots, but without effect. Last 
winter, however, instead of digging in manure about the same quantity 
of peat and sand was dug in, and before sowing a good watering with 
gas-water was given, and the result of the treatment has been a 
beautiful crop of clean Carrots. At the Gardens, Dunrobin Castle, 
Sutherland, Mr. Melville mentions the Carrot Fly as being always 
troublesome. In most years a good yield is secured by carefully 
trenching, and keeping the manure about a foot or fifteen inches from 
the surface. This year, however, the Carrots were grown principally 
