1859. 



NEW ENGLAND FARMER. 



369 



For the New Engiand Farmer. 

 POTATO BOT. 



theory." I deny that there is any such thing as 

 "theory" touching insect depredation, and the 

 influence of insects, causing this malady. The 

 occular demonstration of their ravages at the 

 Mr. Editor :— I have read with some interest roots dispels all "theory." Occular facts set 

 the communication of "S. H. P.," in your paper i^j^jg g^g^y idea of "theory." 

 of May 14th. The subject to which he refers, is i^^g subject thus known and settled by facts, 

 still one of absorbing interest to agriculturists ; i^gcomes definite, real, unanswerable. Therefore, 

 and the various agricultural journals throughout l^^, "theory" cnn be connected with the question, 

 this continent are discussing the question, ao ijy-gj^her speculation or argument can rebut facts, 

 long an open one, of the cause, and for the rem- Qccular facts show that, the disease in the stalk 



edy of this wide spread malady. In answering 

 ••S. H. P.," I believe I can place before your 

 readers some facts, which will throw ncAV light 

 upon this subject. He says he never has seen 

 •'any statement of the symptoms" of the potato 

 blight and rot. The "symptoms" that blight and 

 disease vviil appear in the potato crop, are re- 

 vealed first by the indications, and the fact that 

 the eggs of the aphis are found in perforations 

 in the epidermis of the potato, and in the eye 

 socket and bud-part of the sprouts, at the time 

 the potatoes are dug, and, as are easily seen, be- 

 fore the tubers are planted. He says, "The dis- 

 ease commences its ravages the last half of Au- 

 gust, or from Ist to 10th of September." The 

 causes of this disease, may be traced to the at- 

 tack of insects. They begin their destruction of 

 the vines, at the vital neck joint of the stalk, 

 nearest to the seed tuber, under ground, and at 

 such time, earlier or later, as influenced by the 

 warmth of solar, or artificial heat, to sprout the 

 tubers. This elementary action, animates the in- 

 sect's eggs, when a living, active, voracious ene- 

 my commences sucking the sap, extracting the 

 vitality and nourishment, which, if retained by 

 the vines, (as was the case thirty or forty years 

 ago,) would cause a continued growth of the 

 plant, long beyond the "last of August, or 10th 

 of September." This shows that the "mischief is 

 not done very suddenly." A slow poison spreads 

 from the point where these insects make their at- 

 tack, and that is the remote cause of sudden de- 

 cay, by cutting off the nourishment. 



The insects, in their larva or grub age, (in 

 their secluded position under ground,) communi- 

 cate the "poison to the juice of the top," which 

 poison is admitted by "S. H. P." He "theorises" 

 for "poison." I point out the enemy, and tell 

 where to find him while communicating the 

 "poison." Let me here ask, if this fact of insect 

 ravages is not far more reasonable to believe as 

 the cause of the "poison," than to theorize about 

 the "temperature at 76" to SO'', or southerly or 

 Bouth-west winds blowing briskly, or more or lees 

 rain, or heavy mist, or fog." Is it possible that, 

 this "wind blowing briskly" can be seen on the 

 potato or plant, so as to be recognized, definitely, 

 as a "symptom" of disease ? 



What have these various influences which have 

 always existed, to do now in causing the potato 

 blight, that they did not exercise forty years 

 ago ? Why does this "atmospheric influence or 

 epidemic." act so destructively upon the potato 

 now, and leave the corn, beans, tomatoes and 

 other vegetables in perfect health and vigorous 

 growth, the same as forty years ago P You, and 

 all must admit, that something acts upon this 

 plant now, that did not seriously affect it previ- 

 ous to 1813. "S. H. P." asserts that, "if this 

 poison in the top is correct, it upsets the bug 



'commences at, and spreads from the point at the 

 iroot where the larva aphis makes the attack ; 

 I and no brown rust, or poison appearance, can be 

 [found on the stalk, or at the roots, except on 

 vines where these insects are found subsisting. 



By dissecting such stalks, at the more miture 

 stage of their growth, commencing at the end 

 next to the old parent tuber, a brown, rusty ap- 

 pearance is found, and a withered appearance of 

 that end of the vine. From this point, the brown 

 rust can be traced, with the natural vision, into 

 the capillaries of the stalks, and thence the pois- 

 son is re-transmitted through the stem to the 

 growing tubers, and is imbibed in the latter, in 

 proportion to the virulence of the attack. It min- 

 gles with the healthy, vital, life-sustaining ele- 

 ment of the plant. Its progress and the result may 

 be compared to a reptile's poison flowing from 

 the spot where the poison fang is placed, through 

 the veins to the vitals of the unfortunate object 

 attacked. The blight in the plant follows the in- 

 sect's attack. The vines above the ground and 

 tubers at their roots sympathetically show the 

 influence ; the principle being the same as death 

 to a human being from the poison fang of the 

 reptile. The insects deposit their eggs in the 

 epidermis, the sprout, or bud-part, while the tu- 

 ber is very young and growing, and are firmly 

 imbeded in the trunk or embryo of the vine for 

 next year. In this nidus, they are hibernated. 



When the tuber is planted, as before describ- 

 ed, the insects start into life, and by the instinct 

 of the parent, placed where surrounded by juice, 

 or sap, they pump or draw it from the vine. 

 Thus, while subsisting in a suctorial manner on 

 their natural element, they poison and deteri- 

 orate the plant. The secret source of this mala- 

 dy is found here — these secluded enemies inhe- 

 rently transmit this world-wide disease from one 

 generation of tu'^ers to those of the succeeding 

 year's growth. Microscopic research unfolds the 

 mysterious works of the Great Creator. By thus 

 viewing, with microscopic power, the minute 

 particles of dust, (as seen by the natural vision,) 

 we learn facts revealing His power, and showing 

 our own superficial knowledge. Year after year, 

 scientific men and agricultural laborers, have 

 tasked their utmost talent and powers to little 

 purpose in revealing the cause of this wide-spread 

 malady. But more recently, the microscope has 

 revealed the botanical condition of the tuber, 

 showing clearly the entomological connection, 

 and the cause, and thus pointing out the foun- 

 tain from which this malady springs. The array 

 of insects at the roots of the plants is an occular 

 demonstration, that no theorizing or arguments 

 can repel. It is no "bug theory." There is a 

 real aphis sucking the vitals of the plant. Their 

 eggs and the definite embryo have been searched 

 out, and made visible with the microscope, as be- 



