1837] 



FARMERS' REGISTER. 



237 



inltM'.teJ <rrairis were foiinil in a gpike othor\vit:e 

 licahliy; itml airain, llie diseased urains are seen 

 si-aiJenni in dilltTcat parts of the s|)ii<e, inlerniix- 

 eil with tile healiliy "ties. Ileiiee, it would ap- 

 pi-ar Mr. Bauer <>'eneralizes too liir, when he says 

 tiiat "the inlecied ji^raiiis are always in the last 

 spikelet of ihe ear." Mr. Bryant, indeed, niak'es 

 a remark quite the reverse of Mr. IJauer, l()r he 

 says, "in those ears wliirh are [lartially brairded, 

 tlie diseaset! parts are always seati-d bcncalh the 

 sMund and healthy." (Causes of Brandy p. A9.j 

 In a quantity of infected irrain whieii liiriiisjied 

 twelve ounces ami three drachms of canker, the 

 Abbe Tessier touiid only three ounces ol' sound 

 wheat. 



JNI. Duhamel having more than once found 

 smut and canl<er on the same spike, was led to 

 believe that canker was only the earlier staire of 

 smut; but the conclusion, as will alierwards be 

 seen, is not supported by recent discoveries. (Til-, 

 let, Cause qui Corrompe, p. 75. J 



Cankered urain is ot" a rather oblonjx form, une- 

 qually rounded, and upon the whole reseinblinir 

 sound wheat. At one of the extremities two pro- 

 jecting threads, the remains of tiie stigmata, and 

 at the other the fibres of the bran-envelope or 

 skin approach, while there is no germ, and the 

 usual iLirrow is not so deep as in sound wheat. — 

 The color ol" the grain is greyish-brown, and with 

 a magnifving-glass it appears wrinkled like the 

 outside of a puti-ball (Lycoperdon.) The inte- 

 rior is filled with a fine black [lowder, trreasy to the 

 touch, and wuhout taste, and smellins; tis already 

 remarked of putrid fish. When it has been some 

 hours infused in water, and then examined by the 

 microscope, it appears as a mass of semitranspa- 

 rent globules, very distinct, and adhering to each 

 other as if pressed together. According 'o Tes- 

 sier, they vary in diameter from the 140th of a 

 line to the 2S0th, while those of wheat vary from 

 the 70th to the 560th of a line. Mr. Bauer re[)re- 

 sents the globules of canker as nearly equal in 

 size, and of the 1600th part of an inch in diamter, 

 — shewing that 2,560,000 would cover a square 

 inch. The grains of canker are very light; a 

 measure which contained ten ounces of wheat, 

 havinir been filled with lour ounces and a drachm 

 of cankered grain, of which six drachms were 

 chaff. 



3. Mast or Mildew 



This in England is termed red-rust; by the Ital- 

 ians, La ruggirie del graiin; and by the Fiench, 

 Larouille. It chiefly attacks wheat and barley, 

 but is also found on other grasses and reeds. — 

 C Greville, Flor. Edin. 433.^ 



It has been longer understood than the preced- 

 ing diseases, having been first, we believe, eluci- 

 dated in 1767 by the researches of Fontana ( Os- 

 servazioni sopra laruggine,) who gives tolerably 

 good magnified figures of the rust; and subse- 

 quently by Duhamel, Tillet, Tessier, Kirby, and 

 more particularly by Sir Joseph Banks and Mr. 

 Bauer, who have given admirable figures of the 

 parts of plants afl^ected. It first makes its appear- ' 

 ance on the upper leaf, and then on the lower 

 leaves and the stem, in the form of small white 

 spots, scattered irregularly like spots made by 

 rain on new cloth. These spots gradually in- 

 crease in size and number, and assume a reddish 

 tinge, and at length form a sort of dust-lookmg 



powder, of an ofhre or orange yellow, little cohe- 

 sive, and without smell or 'taste, and, thercl(.)re, 

 very dilierenl h'om canker or smut. It stains the 

 fiuiiers yellow, as well as the clothes ol those who 

 walk amongst the inlt-cled corn. 



The dusi-like substance of the rust oriirinates 

 beneiith the outer btirk or epidermis of the plant, 

 which it raises up, renders thin, and at leiiijtli 

 cracks and bursts throuiih. When examined by 

 the niicroscojie, it presents a congeries ol cira- 

 oblong liodies, some of which have projections al- 

 most like tad-poles or pnwlicads, though they are 

 not animated, as M. Ginani seems to suppose 

 ( Delk Malalie del Grano), for, when the Abbe 

 Tessier put them into warm water, it did not 

 cause them to move. (^Maladies des Grains, 

 p. 201). 



Wheat is attacked with the red rust at different 

 periods of vegetation, but more [larticularly when 

 in the ear. When the rust seizes young plants, 

 they are said to suftiir less than when they are 

 more advanced, often recovering vigor before 

 blooming; whereas at a later period they sustain 

 irreparable damage, and crops which promise well 

 are often in a short time rendered comptiratively 

 worthless. In this case the texture ot tiie leaves 

 is disunited, and presents only longitudinal fibres 

 of a brown color, while the joints and the tubes of 

 the straw between are blackened as if" they had 

 been scorched by fire, the growth ceases, a por- 

 tion of" the ear becomes j'ellow, another [)ortion 

 remains green, and the grain shrivels up in the 

 husk without attaining maturity. 



The evil, however, is rarely carried so far as 

 this, and the yellow spots of rust become choco- 

 late-brown or black, without disorganizing the 

 portions of the plants where they occur; and the 

 Abbe Tessier says he has seen, after heavy rains, 

 the clothes of" the reapers str,"ned with this black 

 substance of the rust as if they had been dipt ii> 

 ink. But, though the plants are not disorganized, 

 the flow of ihe sap is interrupted, the ripening of 

 the grain is prematurely hastened, and it is hence 

 light, containing a small proportion of f"urina, 

 while the straw is bad. Sometimes the rust only 

 leaves a yellow powder on the husks and the un- 

 perend of the grains, taken by Fontana and others 

 to be a dilferent species. 



Sometimes rust prevails so extensively that lew 

 fields escape; but for the most part it is observed 

 in fields sheltered from north winds by wallsj. 

 hedges, or woods, or where ve<jetation is very 

 luxuriant on account of fresh soil or abundant 

 manuring. Sometimes one part of a field escapes 

 while the other is attacked; sometimes the chief" 

 plants, and at other times the side shoots tillering 

 fi'om them, are afi"ected; and sometimes rusty and 

 sound plants grow f"rom (he same root. 



We are not by any means certain whether thia 

 is the same as the mildew described by Alr» 

 Kirby* (Linn. Trans, v. 123,) who makes it 

 very distinct, however, from the red gum and 

 blight. In the year 1797, he says, the wheat 

 sufiijred much by mildew, as ourf"armeis common- 

 ly call it, by far the worst enemy of that grain. — • 

 The ears that were injured by it, were to be dis- 

 tinguished at a considerable distance by their 

 blackness; and when brought close to the eye 



*ProbabIy Uredo linearis, Pers. 

 Sowerby. 



U. longissima, 



