ANSWERS TO CIRCULAR NO. 7. [91] 



when his lands are in good tilth and the work will prove advantageons to the plant 

 cultivated, will never have his cotton injured by the invasion of the Cotton Worm. 

 I deem it unnecessary to go into detail, as my theory and plans have been elaborated 

 in previous correspondence. 



I have the honor to be, yours, respectfully, 



E. H. ANDERSON. 

 Prof. C. V. Riley, Chief U. S. E. C. 



[Dr. A^nderson's theors^ referred to in the above report, and as set forth in an exten- 

 sive correspondence, may be thus stated: In 1858, in the month of July, on visiting 

 his cotton held early in the morning, he found his overseer running a number of plows 

 on a hill-side adjoining bottom land, where the soil was wet. He ordered the plows 

 to be stopped, believing that the work would jfire the cotton and cause it to shed, and 

 perhaps injure the land by baking the wet sod in the hot sun. In ten days the worm 

 was discovered in the cotton, and in twenty days there was not a leaf or young boll 

 to be found upon it, and what especially surprised him was that the worms did not 

 touch adjoining cotton or cross the plowed furrows. Since that time he has often 

 witpessed a similar occurrence, and others have had a like experience, so that he 

 gradually came to consider that there was cause and effect. He made experiments 

 which seemed to confirm that belief, and finally reached the conclusion that either 

 the moth, unobserved, had deposited her eggs upon the stalks, or the eggs of the pre- 

 vious season bad fallen to the ground with tbe leaf of the plant and, being protected 

 by the detritus, had survived the winter. To use bis own language : 



" Under ordinary circumstances, from the albuminous nature of the ^^^, it would 

 be affected by heat and moisture naturally; that is, by solar action on rain and dew, 

 creating vapor, which quickens it into life, by inducing fermentation and putrefaction, 

 without which no egg could be hatched and no germ vivified. Under the influence 

 of cold these chemical forces would be dormant, and the embryo or germ would re- 

 main quiescent. The necessary atmospheiic conditions do not recur annually for the 

 speedy propagation of the Anomis, and hence we do not have them in destructive 

 numbers except in propitious seasons. * * * It is a fact, patent to all practical 

 farmers, that, if their land is plowed while wet or too wet for good tilth, the corn or 

 the cotton, as the case maybe, is injured thereby — fired, as it is termed: the corn 

 turning yellow and being arrested in its growth, while the cotton sheds its leaves and 

 droops. Why is this? I should say because the clod is exposed to rapid solar evapo- 

 ration, and the hot steam damages the plants, through its respiratory organs, and ira- 

 .pedes the normal functions of all of its organs by disturbing the healthy equilibrium 

 of the air. That an abnormal degree of heat is produced by this process is proved by 

 the application of the thermometer, as I know by experiment ; and every farmer knows 

 that the hottest and most oppressive work is plowing wet land under a hot sun." It 

 cannot need proof to show that when by plowing you disturb the capillarity of the 

 earth while damp, abnormal heat is produced by the more rapid evaporation of the 

 upheaved soil. This is as certainly true as that a shower, by restoring or re-establish- 

 ing capillarity, will cool down the earth. 



** Now, my theory is that the damp artificial heat produced by the process of plowing 

 wet land is the most favorable of all conditions for hatching speedily the eggs of tb© 

 insects, and especially when you add to this the extrication of ammoniacal gases, which 

 under such circumstances must be more abundantly evolved. This I hold to be the 

 solution of the mystery of speedy generation in the wetter portion of Cdtton fields." 



The plan of prevention Dr. Anderson proposes on this theory is, never to run the 

 plow in May or June south of his latitude, or in July or August" farther north, when 

 the land is wet and not in good condition for plowing. If there are frequent rains, 

 he believes it matters little when or how the plowing is done ; ''for so long as the rain 

 continues the necessary physical conditions cannot be produced — shower succeeding 

 shower in rapid succession keeps the temperature of both air and earth cooled down 

 and is inimical to the worm. When, however, showers at longer intervals occur, and 

 the temperature i-S high, and the plowing produces rapid evaporation, and the plow- 

 man, reeking with sweat, pants for a breath of pure, dry, fresh air, then the Anomis, 

 nurtured into life by its genial surroundings, commences its revels, and in a short while 

 the luxuriant cotton is converted into .bare and blackened stalks." 



" You must make cotton as you make hay ; that is, while the sun shines. The dili- 

 gent farmer who keeps even with his work can always afford, without d< triment to 

 his crop, to let his plows rest until he can do good work, but if plow you must, to kill 

 grass, and the rain won't stop, ihrow your furrows into the middle of your rows and 

 not to your cotton, as by this process the danger of developing the worm is less, and 

 no injury is done to your plant. 



Dr. Anderson, nevertheless, admits that "afewof the insects are annually hatched 

 by a nutural process: enough to perpetuate the species." A similar theory to this 

 one of Dr. Anderson's is held by a number of planters, founded, of course, on the ob. 



