later, with no appreciable further development above ground and with almost continuous rain, the tap-roots of two other plants examined had penetrated to a depth of about fourteen inches, having gone eight inches into a hard red-clay subsoil which had never been reached by a plow. A photograph taken at this time is reproduced in Fig. 2. The tap-root is about two inches longer by actual measurement than would appear in the figure, as the camera was much higher than the end of the root, and the scale was not close up to the root, but rested against the subsoil, which had not been washed away back to the root. Only one tap-root has been found longer than this during the season's observations on our soil. The average length of the tap-roots of all the plants examined up to the time of their maturity was about ten or twelve inches, and the general impression that the tap-root completes its growth in length before the growth of the plants above ground begins seems to have been entirely confirmed in this instance. Another proof of this is that the length of the tap-root is in a measure independent of the character of the subsoil and of the size of the plant, as was shown very decidedly during the course of this investigation. In Fig. 4 can be seen plants with six to eight times more bolls (from 75 to 117) than the average given above, growing without manure or fertilizer, over a deep loam subsoil, with tap-roots only ten to fourteen inches long. The lateral roots are, for the most part, confined to the space from three to eight inches below the surface, and on this land were generally found spread out just on top of the clay subsoil, as though it had been a table. In Fig. 3 this is not shown so well as in the original photograph, as the roots were allowed to hang over the ledge of subsoil when the photograph was taken. At this time the lateral roots were observed from one to three feet long. The figure shows very well the development, or rather lack of development, of the tap-root. The stem of the plant seems to enlarge somewhat below the surface, tapering off to nearly a point four or five inches below the surface, while below this there seems to have been little or no development of the tap-root in the four or five months of the active growth of the plant. This can be seen quite well in the photographs of the larger and more mature plants in Fig. 4. Here also can be seen how the lateral roots spread out in a layer of only about four inches in depth, beginning from about three inches below the surface. These plants in Fig. 4 were grown, as stated, without manure or fertilizers, over a deep loam subsoil. They averaged nearly five feet high, with several branches of nearly the same length. Most of them had from 75 to 117 bolls, besides a large number of forms. One lateral root was followed 9 feet 11 inches when it was broken off about a foot below the surface, the direction being at this point downward. It was estimated that on these plants there were on an average fifteen roots with an average length of, say six feet. Without counting the many branches and shorter roots proceeding from the main stem, this would give a root system of nearly one hundred feet for the principal frame-work and main arteries, for the support of the plant and as a channel for the transmission to the plant of the food gathered by the finer hair-roots. These roots, for a considerable distance around the plants, must be closely matted, for in following out a root, at a point between the rows four feet from any plant, in a space of six inches, eighteen roots were counted hanging over one side of the channel. As was stated, the tap-roots of these plants, so far as observed, were no longer than those of the smaller plants above described. The lateral roots generally were deeper and could not have had so much heat as the shallower-rooted plants, which may possibly account for the larger plants not having matured, and but few of the bolls opening before severe cold weather. Both the clean culture and shallow cultivation usually given to cotton tend, by keeping the ground warmer and the roots nearer the surface heat, to mature the crop earlier, a very important point in cotton production in this State. The root system of the cotton plant is quite different from that of either tobacco or cow-peas, so far as we have observed. Some tobacco plants grown only a few feet from these large cot ton plants just described had tap-roots thirty inches or more in length and lateral roots five and six feet long, but generally deeper than the cotton, and with many more shorter roots directly under the plant. Our observations on the rooting habits of the tobacco were not so full as in regard to cotton. In the course of this work it was frequently observed that decaying organic matter, as old roots and the like, were often enveloped in a mass of fine roots thrown out from a main stem of the growing plant. 123 Date. Air. 3 in. 6 in. 12 in. 24 in. Air. 3 in. 6 in. 12 in. 24 in. Air. 3 in. 6 in. 12 in. 24 in. 1 66.0 68.8 70.0 71.2 71.0 67.0 68.5 69.8 70.4 71.0 69.0 68.2 69.0 70.0 70.6 2 66.0 68.2 68.7 69.5 70.1 78.6 74.1 71.2 70.0 69.9 76.2 75.4 74.6 72.5 69.9 3 66.8 68.8 69.6 70.8 70.2 76.0 78.7 75.2 72.1 70.2 76.7 78.6 77.9 75.0 70.2 4 69.0 70.4 71.2 72.2 71.0 82.0 84.5 79.3 74.5 71.0 75.7 78.9 79.5 77.4 71.1 5 69.9 71.7 72.9 73.5 71.7 79.9 84.1 78.6 74.5 71.8 75.6 79.3 80.1 780 71.9 6 71.0 72.5 72.8 73.8 72.2 79.8 83.7 79.8 75.1 723 71.0 77.0 79.0 78.0 72.2 71.0 72.9 73.0 73.8 72.6 82.3 80.1 79.6 75.5 72.7 79.6 81.2 80.8 78.1 72.5 75.0 73.5 73.7 74.8 73.1 83.5 84.5 80.2 76.3 73.1 82.2 81.6 80.9 787 73.0 70.1 729 74.8 73.5 83.8 86.7 82.0 77.0 73.5 82.8 84.0 82.7 79.9 73.5 10 72.5 73.7 75.5 74.0 87.2 87.0 81.8 77.2 74.0 70.1 79.1 81.5 80.0 73.8 71.8 72.5 74.9 74.2 84.0 87.5 82.2 77.2 74.2 80.0 82.1 82.0 79.9 74.0 12 71.8 72.8 74.2 76.0 74.4 85.0 87.0 82.1 78.Q 74.5 73.4 79.0 80.0 79.1 74.4 13 68.5 71.8 73.0 74.9 74.5 81.2 85.5 80.2 76.5 74.5 80.4 83.1 81.9 79.7 74.4 14 73.5 74.5 75.0 76.3 74.8 880 88.0 81.5 77.8 74.8 75.5 81.6 813 80.0 74.8 15 65.9 69.8 72.2 75.0 74.9 75.9 78.2 76.0 74.6 74.8 70.0 74.3 75.8 75.8 74.5 16 68.0 70.0 73.0 74.0 79.5 83.3 77.2 74.0 73.9 76.1 79.4 79.4 77.2 73.5 17 66.4 68.9 71.3 73.7 73.8 81.2 85.3 78.5 74.8 73.8 78.5 81.5 81.7 78.6 73.7 18 68.7 71.2 73.0 75.0 74.1 85.0 87.8 80.6 76.5 74.2 80.8 84.1 84.0 80.3 74.0 19 70.5 72.0 74.1 76.1 74.7 85.9 89.6 82.0 77.5 74.7 82.3 85.5 84.8 81.1 74.7 20 70.3 73.6 75.6 77.2 75.2 83.8 88.6 82.0 78.2 75.3 79.0 84.2 83.7 81.0 75.3 "21 75.5 74.1 75.7 77.1 75.7 82.1 81.7 78.8 77.5 75.6 79.9 83.1 81.7 79.5 75.5 22 69.3 73.3 75.2 76.8 75.5 83.2 89.4 82.0 78.0 75.6 80.9 86.5 85.5 81.7 75.5 23 70.5 73.4 75.2 77.2 76.0 84.4 91.7 84.1 78.9 76.0 82.1 87.0 86.2 82.3 75.8 24 70.8 73.5 76.0 78.0 76.5 86.6 91.1 84.1 79.4 76.5 80.7 85.5 85.0 82.2 76.3 25 68.0 73.8 75.9 77.9 76.7 84.8 92.0 84.3 79.4 76.7 82.0 86.9 86.1 82.6 76.6 26 70.8 74.0 76.2 78.3 77.0 88.5 92.9 85.0 80.0 77.0 86.0 89.0 87.8 83.7 76.9 27 72.5 76.5 78.4 79.7 77.4 87.4 88.8 83.4 80.3 77.5 84.9 87.3 85.9 82.7 77.3 71.9 75.6 77.8 79.4 77.6 88.7 94.2 86.0 80.9 77.7 85.1 89.7 88.4 84.5 77.7 74.1 77.1 79.0 80.5 78.2 91.1 95.0 87.6 82.1 78.2 86.5 90.9 89.7 85.8 78.2 30 76.5 79.3 80.8 81.9 79.0 91.0 94.0 88.7 83.6 79.0 85.2 90.5 89.4 86.0 79.0 31 75.0 79.4. 81.0 82.1 79.3 90.0 94.1 87.7 83.3 79.4 84.9 89.7 88.5 85.6 79.4 Mean. 70.6 72.9 74.2 75.8 74.6 80.9 86.4 81.0 77.1 74.6 79.1 82.7 82.4 79.8 74.5 |