NOTES AND ABSTRACTS. 
217 
length, and the ring at the other end is fixed in the same way. The measure- 
ments along the wire should be accurately made, allowing for an overlap of 
4 or 5 feet at each end of wire between the ring and the first mark on the wire. 
Commencing, then, at a point, say 4 or 5 feet from the ring, a piece of copper 
wire is wound round the measuring wire and soldered into position. This plan 
is continued every 20 feet or whatever distance between the trees is decided 
upon. The use of copper wire for markings is preferable to paint, as the latter 
is liable to be rubbed off, and copper markings will be as readily visible as paint 
when pegging is being done. About 20 feet is required for the headland. — C. H. H. 
Melon Fly, The. By E. A. Back and C. E. Pemberton (U.S.A. Dep. Agr., 
Bull. 643, March 1918; 23 figs.). — 'The Melon Fly (Bactrocera cucurbitae Cog.) 
was introduced into Hawaii about 1895 bv Japanese emigrants in fruits which 
they brought with them as food from Japan. 
Before its introduction, cantaloupes, water-melons, pumpkins, cucumbers, 
etc. were grown in large quantities, but the ravages of this pest prevent these 
crops being grown by the average person, and only under great difficulties by 
the market gardener. 
Since there are eight to eleven generations of the Melon Fly a year, and 
the females live to be over a year old and lay eggs throughout life, the pest 
can multiply very rapidly. 
No satisfactory methods have been yet discovered to control this fly under 
Hawaiian conditions. — -V. G. J. 
Mesopotamia, Vegetation of. Anon. (Irish Gard. 13, p. 183 ; Dec. 191 8). — 
Notes on the plants grown by Arabs, both vegetables and flowers. — F. J. C. 
Millipedes, Preliminary Notes on Control of, under Sash. By J. Horsfall 
and J. R. Eyer (Journ. Econ. Entom. vol. xiv. pp. 269-272, June 1921). — The 
experiments were conducted with seedling lettuce. Sodium cyanide applied 
at the rate of 150 lb. an acre, in furrows and covered with soil one week before 
seeding, resulted in comparatively perfect stands of lettuce. 
Nicotine sulphate (\ per cent.) sprinkled on a newly seeded bed also compared 
favourably with the control plots. Poison bait was satisfactory in the spring, 
but failed as a protection in the autumn. The best formula was : 
2 pecks bran, |— 1 pt. molasses, 2 oz. sodium arsenite and water sufficient to 
make a mash. — G. W. G. 
Mosquito Control in a Southern Army Camp. By S. M. Dohaman (Jour. 
Econ. Entom. vol. xiii. pp. 350-354 ; 3 plates ; Aug. 1920). — The paper deals only 
with mosquito control in a large camp, south-west of San Antonio city, Texas. 
The best admixture of oils for spraying pools and all apparent dangerous 
sources of mosquitos was found to be a combination of crude oil (70 per cent.) 
and kerosene oil (30 per cent.), pending the adoption of more permanent control 
measures. It is interesting to note that one of the duties of the camp ento- 
mologist was to collect bi-weekly specimens of mosquitos found in the camp, 
which were sent to the Army Medical Museum, Washington, for a study of the 
relation between disease-carrying mosquitos and local prevailing diseases. 
The treatment of a sluggish creek close to the camp is fully dealt with and 
illustrated. A system of drip oiling from a 50 -gallon drum, fixed so that ripples 
caused by a large stone thoroughly dissipated the oil and distributed it to the 
sides rather than the centre of the stream, was arranged for during operations. 
Close attention here was necessary so as to secure efficient oiling without killing 
the top -minnows present in the creek. A central channel was cut along the 
entire length of the creek and graded so as to ensure a steady flow and not 
leave undrained pools ; and the work was eventually completed by turfing the 
banks so as to withstand washouts by the heaviest rains. — G. W. G. 
Mutations: Mass Mutations and Twin Hybrids of Oenothera grandiflora 
Ait. By Hugo De Vries (Bot. Gaz. vol. lxv. No. 5, May 1918, pp. 377-422) ; 
6 figs.). — Oenothera grandiflora Aiton from Castleberry, Alabama, splits in every 
generation into two types, one resembles the parent plant, the other consists 
of weak, yellow individuals, of which only a few are vigorous enough to 
flower and ripen their seeds. This latter is called O. grandiflora mut. ochracea. 
As the result of experiments in crossing and in combination with the 
occurrence of about 25 per cent, of barren grains amongst the seeds, De 
Vries arrived at the conclusion that the yearly production of large numbers of 
hracea is a phenomenon of mass mutation, due to an initial mutation of the 
ordinary type, followed by secondary mutation in the succeeding generations. 
Certain crosses led to the production of twin hybrids, which may be con- 
sidered a consequence of the mass mutation, the mutated gametes producing 
one of the twins and the typical sexual cells the other. — R. J. L. 
VOL. XLVIl. Q 
