820 PRACTICE OF AGRICULTURE. Part III, 



parcel as formerly, and in place of it lay in a new straw, which is then to be used exactly as if it 

 were the old one. 



5058. Ifhy chance, in ivorkin^, any of the straws should break, a thing which can scarcely liappen with 

 winle-straes to any but the outermost straw, and to it only through want of attention, it may be reme- 

 died without any more trouble than putting in a new one in its place ; and though the outside of the plait 

 with the old and new straw should exhibit the appearance of a broken loop, yet, in the knitting up of 

 the work, it can easily be so managed that the defect shall be entirely concealed. 



5059. The knitting need not be begun till as much of the plait is made as may be supposed sufficient to 

 form a hat, as an entire hat of any desired shape may be made up of a single piece of plait. About 70 or 

 80 yards will be sufficient to make a lady's hat. 



5060. Outside and inside of the hat. In joining in new straws during the plaiting, the ends of the new 

 and old having been kept on ihe upper side of the plait, this will therefore be made the inside of the hat. 

 After twisting and turning the plait a little, to make it form the round piece for the top, the plait will be 

 found to lie with the one side to the other, like the teeth of two saws turned to each other; and then so 

 to unite these two opposite sides that they may present the appearance of one piece, begin to sew by 

 putting the needle in through the sort of stitch or loop on the outside of the plait, inserting the needle 

 from below. Take the stitch of the opposite piece in exactly the same way, and, after four or five stitches 

 of each side are taken on the thread, draw it up tightly, so that the stitches of both may be brought firmly 

 the one beside the other. In tliis manner, in the course of the operation, it will soon be seen that the 

 place where the seam is can scarcely be discovered from the rest of the plait. 



5061. To sew the crown of the hat so that it may be quite plain, every stitch of the one side must not be 

 taken with every one of the other, but every second or third only of one of the sides, till the work get 

 on a little. 



5062. The blocking of a hat may be done with any round piece of smooth stick that will fill it. After 

 the hat is well steeped, and put on the block, it may be made quite smooth by beating it gently with a 

 hammer. {Quar. Jour. Ag. vol i. p. 294.) 



5063. The diseases of roheat are the rust, smut, or black mildew, the latter including 

 what is vulgarly called blight. These have been already treated of in our view of the 

 vegetable economy, and we shall merely offer a few practical observations on the smut 

 and mildew. 



5064. The proximate cause of smut, in whatever manner the smut may be transmitted from the seed 

 pickle in the ground to the ear, it seems certain, is in general the infection of the seed by the dust of the 

 smut-ball, which B. de Jussieu first conjectured to be Lycoperdon globbsum, and which M< Prevost ascer- 

 tained to be a microscopic vegetable of some sort ; and that though the most careful washing, even 

 with the application of caustics, may not in every case insure against smut, yet if the seed be prepared in 

 the way already mentioned, the disease will never prevail to such a degree as to affect materially the value 

 of the crop. This is all that cultivators need to know, and all, perhaps, in the present state of science, 

 that can be known, of the cause and prevention of smut. See an article at length on this subject in the 

 British Farmer's Magazine, vol. iii. p. 17P. 



5065. Mildew is a much more destructive distemper than smut; and, as it is probably occasioned by a 

 peculiar state of the atmosphere during the periods of flowering and ripening. It is likely to baffle all 

 attempts at prevention. The prevalence of heavy fogs or mist, drizzling rains, and sudden changes in 

 the temperature, have been assigned as the causes of mildew ; and as it has been found that open airy 

 exposures are much less affected than low sheltered lands, in years when mildew prevails most generally, 

 the disorder may perhaps be somewhat diminished by drilling, which admits a freer circulation of air. 

 Spring or summer wheat is less liable to mildew than the winter species, though it does not always escape. 

 Minute parasitical Fungi, Pucciniff Graminis {Enc. of Plants), are commonly detected on the straw of 

 mildewed wheat ; and there caimot be the least doubt that the barberry bush, and probably several other 

 shrubs on which these Fungi abound, have a powerful influence in communicating the disease to a certain 

 distance. {Sir Joseph Bankes on Mildew, and Com. to the B. of Agr. vol. vii.) 



5066. The wheat fiy has, of late years, been one of the greatest enemies to the wheat crop in Scotland. 

 In North America this insect, or one of the same family, has been known for many years, more espe- 

 cially in New England ; and its alarming ravages are depicted from time to time in the newspapers, under 

 the name of the Hessian fly. In the modern nomenclature, the Rev. W. Kirby informs us that the wheat 

 fly, formerly the Tipula tritici Lin., is now the Cecidomyia tritici {fig. 724. a), and the Hessian fly the 



C. destructor (6). The wheat fly generally makes its 

 appearance about the end of June; and, according to 

 the observations of Mr. Shivreff, they exist throughout 

 a period of thirty-nine days. The hue of the fly is 

 orange, the wings transparent, and changing colour 

 according to the light in which they are viewed. It 

 lays it^ eggs within the glumes of the florets, in clusters 

 varying in number from two to ten, or even fifteen ; and 

 thelarvcD feed upon the grain. " They are produced from 

 the eggs in the course of eight or ten days: they are at 

 first perfectly transparent, and assume a yellow colour in 

 a few days afterwards. They travel not from one floret 

 to another, and forty-seven have been numbered in one. 

 Occasionally there are found in the same floret larvje 

 and a grain, which is generally shrivelled, as if de- 

 prived of nourishment ; and although the pollen may 

 furnish the larva with food in the first instance, they 

 soon crowd around the lower part of the germen, and 

 there, in all prol)abilitv, subsist on the matter destined 

 to form the grain." {Mag. Nat. Hist, vol ii. p. 450.) The 

 larv;e are preyed on by the Ceraphron destructor, 

 an ichneumon flv, which deposits its eggs in the body 

 of the larvee of the wheat fly; and this is the only check hitherto discovered for preventing the total 

 destruction of the wheat crops attacked by the Cecidomyia. Mr. Shirreff, speakmg of this ichneumon, 

 savs " I could not determine if it actually deposits its eggs in the maggot's body ; but there can be no 

 doubt however, of the ichneumon piercing the maggots with a sting ; and, from stinging the same maggot 

 repeatedly, it is probable the fly delights to destroy the maggots, as well as to deposit eggs in their bodies. 

 Th^e earw^'g, also^ devours the Laggots as food, i^rit I^rn.J,.g..^l^.^^ 



in 1827, 



loss sustained by the farming interest in the Carse of Gowrie district alone, by the wheat fly, at 20,000/. 

 1827, at 30,000/. in 1828, and at 36,000/. in 189. {Perth Miscellany, vol. i. p. 42.) The same writer in May 

 1830 thus depicts the prospect of the wheat crop in the Carse of Cowrie : " The Cecidomyia are still alive 

 in formidable legions. That the flies will this season be in as great plenty as ever, is now quite certain ; that 

 they will lay their eggs on no other plant than those of the wheat genus, is also true; the only chance of 

 escape is in the time the pup;e appear the Ry state. Should this sunny weather bring them forward 

 within a fortnight or three weeks from this date, the greater part will have perished before the wheat is 



