i49 



FARMERS' REGISTER. 



[No. 4 



ears more advanced in growth, these minute 

 grains assumed a pale red color. At a still more 

 advanced period, the partitions of ihe lour-sided 

 cells disappear, the minute grains, instead of re- 

 maining in contact, become separated from each 

 other, and the whole mass is trauslormed into a 

 heap ol" dust, composed of very regularly formed 

 round black grains, perlijclly resenibling the semi- 

 nal germs of mushrooms. 



It is evident, then, that there is no resemblance 

 between the fleshy mass in the infected loot-stalU, 

 or peduncle of the grain, and the healthy foot-stalk, 

 at whatever period it may be observed. Conse- 

 quently JNl. Ad. Brongniarr thinks hiniseli'perlectly 

 justified i'i concluding, that the affection does not 

 originate in any diseased modification of the natu- 

 ral tissues, but in the growth of a parasite fimgus, 

 whose progress he had thus traced more minutely 

 than had hitherto been done, providing that no 

 previously received opinion is correct. 



M. Bauer appears to have performed experi- 

 ments with smut somewhat similar to those of M. 

 Fee with the rose-rust; but he has not given the 

 details, having only linblished the results. He 

 tells us he has ascertained, by repeated experi- 

 ments of inoculation (how performed he does not 

 Bay), that the seed of smut-fungus ( Lredo segetuin) 

 is absorbed by the roots of the germinating seed- 

 corn, and, being e.Ktremely minute, is mixed with 

 and propelled by the circulating sap, which depo- 

 eites it in almost every part of the cellular tissue 

 of the plant. He adds, that he has not the least 

 doubt that the seeds of the smut-fungus are 

 shaken out by the wind, and that even many in- 

 fected ears and plants are thrown on the soil of a 

 field where infected corn has been growing, and 

 that the smnt-fiangi continue growing and multi- 

 plying on the soil till they become a part of it and 

 cannot be distinguished. 



These views we consider to be scientific and 

 correct, except in so far as the fungi are said to 

 grow on the soil, for this is not proved by obser- 

 vation, and it is probable, t>om analogy, that they 

 would not grow except within the tissues of vege- 

 tating corn or grass. 



2. Ascertaiiud cause of Canker. — The canker or 

 pepper-brand of wheat is proved to be a fiingus of 

 the same genus ( Uredd) as the smut, but of a very 

 different species {Uredo fcetida), well distinguish- 

 ed, as remarked above, by its sniellmg like putrid 

 fish, and by its not bursting the grain, but remain- 

 ing within the outer envelope. 



The most minute account of the progress of the 

 fungus is given by M. Bauer, whose investigations, 

 however, were unlbrtunately previous to the dis- 

 covery of M. Duttochet respecting the vegetation 

 of fungi. The earliest period, he tells us, at which 

 he discovered the fungus within the cavity of the 

 seed-germ (^ovalum) ol" a young plant oi' wheal 

 eown in November, was the 5th of June, sixteen 

 days before the ear issued from the leaf sheath, 

 and about twenty days befl)re the sound ears 

 springing from the same root were in blossom. 

 At this early stage, the inner cavity of the seed- 

 germ {ovulum) was very small; and, after fecun- 

 dation, vvas filled with farinacious substance des- 

 tined to form the flour of the wheat. 



It was then that M. Bauer first observed what 

 he describes as the jelly-like root or spawn, rather 

 the main plants of the fungi themselves, adhering 

 to the lining membranes of the cavities, from which 



they could easily be detached in the form of small 

 flakes. At this period, it is most important to no- 

 tice that JM. Bauer observed very short but distinct 

 fbot-stalks or pedicles seen issuing from the main 

 plant, or what he terms spawn, and supporting the 

 ii'uit. All tlie parts of the fungus are in the early 

 stage pure white, but when tiie ear issue? from the 

 leaf-sheath, the seed of the wiieat {ovum) is much 

 enlarijed, though still relainino; its original shape, 

 and the fungi (or rather we should say the fruit) 

 multiplying rapidly, separate from the mavn plant, 

 assume a darker color, and lie loose in the cavity 

 of the grain of wheat. The grains thus infected 

 continue iirowing, the fungus producing within 

 ihem a great number of fruit, till the period when 

 tiie healthy grains attain maturity, and become of 

 a light brown. Then the inflected grains likewise 

 change their dark green color to a dark brown- 

 When cut in two, the inlected grains are found 

 to be quite filled with the black grain-like fruit of 

 the fungus. 



By inoculating (in what way he does not say) 

 the finest saujples of seed-v/heat, JM. Bauer fuily 

 ascertained that the seetisof, the canker-JunguSy 

 adhering to the wheat, is taken up by tlie germi- 

 nating roots, and carried by the sap to the younirer 

 ears, in the same manner as we have seen, takes 

 place with the smut-fiingus. "Like a troop of 

 sappers and miners," as Professor Burnet says, 

 "the canker-brands carry on all their operations 

 secretly, and often cotriplete their work before its 

 commencement has been suspected." 



3. Ascertained cause of Hud or Mildew. — The 

 rust and various sorts of what are termed mildew, 

 are all caused by small fungi, such as the tuft- 

 brand (Puccinia graminis, Persoon, or Uredo 

 frumenti, Sowerby) and the linear brand {Uredo 

 linearis, Persoon, U. Iargissi7na, Sowerby), which 

 do not differ so much in the injuries which they 

 produce as m their mode of growth and appear- 

 ance, as has been already described. 



The history of the red rust need not detain us, 

 as it has been long well known from the very good 

 account given of it by Sir Joseph Banks, with most 

 admirable drawings by M. Bauer. The opinion, 

 however, which Sir Joseph seems to adopt, is not 

 that the seeds of the rust-fungus get into the corn 

 plants by the tips of the roots, but by the pores, on 

 the leaves and stem being carried thither by the 

 winds, and caused to adhere by the moisture of 

 dew or rain. When once entered into the pores, 

 he says — "They germinate and push their minute 

 roots, no doubt (though these have not yet been 

 traced) into the cellular texture beyond the baik, 

 where they draw their nourishment by intercept- 

 ing the sap that was intended by nature for the 

 nutriment of the grain. The corn, of course, 

 becomes shrivelled in proportion as the fungi are 

 more or less numerous on the plant; and as the 

 kernel only is abstracted from the grain while the 

 cortical part remains undiminished, the proportion 

 of flour to bran in blighted corn is always reduced 

 to the same degree as the corn is made light. Some 

 corn of lasl. year's crop (1804) will not yield a stone 

 of flour fiom a sack of wheat; and it is not impossi- 

 ble that in some cases the corn has been so com- 

 pletely robbed of its flour by the liingus, that if the 

 proprietor would choose to incur the expense of 

 thrashing and grinding it, bran would be the pro- 

 duce, with scarce an atom of flour for each grain," 

 — On blight m Corn. 



