TRIANDRIA. DIGYNIA. Trixicum. 
207 
which, from the spikets facing one way, becomes visible behind through 
its whole length, has a strong wood-like mid-rib, edged with a thinner 
and greener border, as in Poa rigida. 
Sea Wheat. (Dwarf Sea Wheat Grass. (Welsh: Corwenith-wellt y 
morfin. E.) Poa loliacea. Huds. Relh. Sandy sea shores. 
A. June—July.* 
* It maybe here observed that the devastation made amongst the cultivated kinds 
of grain has been fully proved to be caused both by pernicious vegetable and animal 
influence. That very destructive blight, the Mildew or Rust in corn, is now ascertained 
by the microscopical observations of the Sir Joseph Banks and Mr. Bauer of 
Kew, to be occasioned by a minute parisitic fungus, Uredo frementi , allied to Per- 
soon’s division, “peridio nullo , sporulis rotundis uniformibus,” which undermines the 
epidermis of the leaves and stalks, and bursts forth at different places in more or less 
linear, brown or blackish stripes. It is said the earlier crops are less liable to this injury 
than the latter. It first appears on the leaves of corn, early in the spring, in the form of 
rust or orange-coloured powder, afterwards becomes chocolate, and finally ripens black. 
The seeds of wheat are rendered so lean and shrivelled by the exhausing power of the 
fungus, that scarce any flour fit for making bread can be obtained by grinding Ihem. 
How far such grains will answer the purpose of seed-corn, is disputed, though the Editor 
cannot but incline to favour the opinion that sound seed must be sown to insure a good 
crop of prime corn. An account of this species of blight, with excellent figures, may be 
seen in the Annals of Botany; and in an appendix to Curtis’s Practical Observations on 
British Grasses. See also Mr. Kirby in Linn. Tr.; Felice Fontana’s Essay, 1767 ; 
and the New Farmer’s Calendar; vid. Uredo, and a further note on this important 
subject, With. vol. 4, p. 372. Nor may it be irrelevant to add that, among 
the insect tribe, the commonly reported enemy to grain is the Grub, (of the Tipula or 
Crane-fly), and the Wire-worm or Root-worm, of which there are several species; but in 
the 9th vol. of the Linn. Trans, we find an important paper, accompanied with a plate, 
of a nondescript insect, which the author, T. Walford, Esq. supposes to be the prevalent 
Wire-worm of Essex and Suffolk, so destructive in the months of October and November. 
‘'With their projecting jaws these insects cut round the outside grass, about an inch 
below the surface of the soil, to get at the young white shoot in the centre, which they 
eat; upon this, vegetation is immediately stopped, and the plant dies. They are also 
charged with eating the flour in the grains not yet drawn out of the soil; their habita¬ 
tions are the husks. From continued observations, Mr.Walford calculates the number of 
acres annually destroyed in England by these noxious insects to be not less than 60,000 ! 
Early ploughing is advised as the only preventive, and the free use of unslacked lime, 
the most probable remedy for this extensive devastation,—alarming indeed—did we not 
consider the miraculous power of increase in a single grain of wheat. In 1768, Mr. 
Charles Miller made experiments on the sowing of wheat and dividing the root, by 
which means were produced in one year, from one grain, 21,109 ears, which yielded 
three pecks and three quarters of dean corn, weighing 47 pounds and 7 ounces; and 
the number of grains calculated by the number in one ounce, might be 576,840, vid. 
Phil. Tr. v. 58. The fly, Musca pumilionis, introduces its eggs into the heart of the 
shoots of Rye, occasioning many to perish. A small moth also, Pyralis secalis, eats the 
culm of the plant, within the vagina. See Linn. Tr. ii. The wolf, and the weevil of 
Leewenhoeck, have been long noted for their depredations on different kinds of grain. 
The gelatinous larva of a saw-fly, Tenthredo, preys upon the upper surface of the leaves 
of Barley, occasioning them to wither. Musca hordei, of Bierkander, also assails the 
plant; and a small species of moth devours the grain when laid up in store, concealing 
its eggs in the corn, and perpetrating its ravages so clandestinely that millions may exist 
in a heap of corn, without an individual being suspected. Many minute insects which 
may be observed coursing about the ears of corn, as Phalacrus corruscus, (in Retie. Sege- 
turn), subsist on the fuhgilli that infest the grain ; others attack the grain itself, as (Ecido - 
myia tritici ; others destroy these destroyers. Of such are the ruthless Ichneumones 
minuti, w'bich, with their penetrating ovipositors, restrain within destined limits the infi¬ 
nite host of lepidopterous and other larvae, searching even their most secret recesses. 
These larvae actually form a nidus for the eggs of their exterminating foe ; and thus, by 
