NOTES AND ABSTRACTS. 
495 
Hardy Heaths for the Rock Garden. By H. S. W. (Irish Gard. xi. p. 113, 
Aug. 1916). — A useful list of hardy heaths suitable for a rock garden. — F. J. C. 
Horse-chestnut Leaf-blotch. By V. B. Stewart (Phytopathology, vi. pp. 5-20, 
Feb. 191 6 ; pi.). — A full account of the isolation and study of the fungus 
Guignardia Aesculi (Pk.) Stewart, and of the disease in the form of a red 
irregular blotch which it produces on leaves of Aesculus Hippocastanum and 
A. glabra.— F. J. C. 
Horse Chestnut Leaf-blotch. By V. B.Stewart (U.S.A. Exp. Stn., Cornell, 
Bull. 371, Feb. 1916 ; figs.). — The leaves are at first slightly discoloured and 
water-soaked ; the central part of the affected area becomes dark red to brown 
with a yellowish margin, and finally dries and dies. Minute black specks may 
be seen scattered over the spot. The fungus is sometimes found on the petioles, 
and similar spots occur on the fruits. Nursery stock suffers most. The cause 
of the disease is Guignardia Aesculi (Peck) Stewart. Both lime-sulphur and 
Bordeaux mixture proved effective, as did dust-spraying with sulphur and lead 
arseniate (see above, " Apple Orchard "). — F. J. C. 
House-fly, Distribution. By R. R. Parker (Jour. Econ. Entom. vol. ix. p. 325, 
June 1916; figs.). — House-fly, Breeding Habits. By A. T. Evans (ibid. p. 354). 
Large numbers of marked house-flies were liberated at certain points in a town 
and many recaptured at distances varying from fifty yards to two miles from the 
point at which they were liberated. The search for (and smell of) food and suit- 
able situations for egg-laying appear to be the causes contributing to this wide 
distribution. The experiments were carried out in a town and do not relate to 
country conditions. In the second article accounts are given of searches in 
garbage pails and rubbish heaps and in manure heaps for the larvae of the house- 
fly, which were, except in one instance, only found in the last. The manure was 
alkaline in reaction and the garbage acid, the solitary case in which house-fly 
larvae were found in a garbage pail occurring when the garbage was neutral. 
All strengths of hydrochloric acid were found to inhibit the hatching of eggs or 
development of larvae. Manure stored in bins proved a bad place for the develop- 
ment of house-flies, owing to the growth of moulds on the surface of the manure. 
The larvae are very sensitive to moisture and leave the manure when it becomes 
too wet. — F. J. C. 
House-fly in Relation to the Farm Manure Heap, Some Experiments 
on the. By H. Eltringham (Jour. Agr. Sci. vol. vii. pt. 4, pp. 443-457, April 
1 91 6 ; figs.). — The object of the experiments was to test the universally accepted 
belief that all manure breeds house-flies. Experimental heaps of manure from 
a variety of sources, and varying in their degree of compactness, were established. 
They were covered in such a way that all flies hatched out were trapped. In 
only one case was any considerable number of Musca domestica found. In this 
instance a quantity of horse manure was obtained from a stable closely surrounded 
by houses and adjacent to a bakery. The number of flies hatched out was 865, 
and of these 798 were house-flies. With this may be contrasted the hatching 
from a heap of manure near farm buildings, but remote from houses (excepting 
two cottages 70 yards away). Out of some 1,200 flies hatched from this heap 
only three were house-flies. From nineteen such experiments the author con- 
cludes that, whilst the house-fly breeds in large numbers in stable refuse which is 
stored in close proximity to dwellings, the governing factor is found in the 
dwellings rather than in the manure heap, the latter serving as a secondary 
convenience for flies which are attracted to the human habitations in search of 
food. Incidentally it was observed that farm manure heaps far away from 
houses, though but little frequented by house-flies, are a prolific breeding-ground 
for Stomoxys calcitrans, a blood-sucking insect which torments farm animals, 
horses in particular. — /. E. W. E. H. 
Humogen, Experiments with. By C. T. Gimingham (Ann. Rep, Agr. 
Res. Stn., Long Ashton, 1915, p. 110).— In these experiments, carried out in 
pots with tomatos, humogen or bacterized peat gave a higher yield than any 
other treatment tried when used at the rate of 1 lb. to a pot in which one tomato 
was grown; i\ lb, (average 1,259 grammes) stable manure and nitrate of soda 
came next (1,160 grammes), while heated but not bacterized peat used at the 
rate of 1 lb, to the pot gave 827 grammes, the control giving 374 grammes average 
only. The humogen contained 2*39 per cent, nitrogen, the heated peat ro8 
per cent., and the manure 0-49 per cent. ; and the author considers the extra growth 
obtained is to be accounted for by the amount of nitrogen supplied. F. J. C,_ 
