10 



be also directed to the isolation in a condition of purity of those types 

 yielding lint most nearly approximated to the class standard. 



Deterioration has been repeatedly referred to as if it were a 

 condition inherent in the plant. The particular variety is, in this 

 view, supposed to possess a more or less definite span of life, after 

 which degeneration sets in and the lint product gradually deteriorates 

 in quality. The word is unscientific and, as commonly and loosely 

 applied, probably covers a number of phenomena. But, in as far 

 as it implies a degeneration in the plant, it is unsound and finds no 

 basis in fact. The cotton plant is notably freely cross-fertilized, and 

 the presence of a single impure plant in a field is capable of producing, 

 in the course of a few seasons only, a degree of impurity which will 

 surprise, and hardly be credited by, those who are unfamiliar with the 

 phenomenon. Given initial purity and adequate protection from chance 

 cross fertilization, this explanation of degeneration will be found to be 

 fallacious. In selection and propagation under conditions which 

 adequately meet the ever-present tendency to pass from purity to 

 impurity, will be found the means of maintaining the uniformity 

 desired by the spinner. 



There remains the third desideratum expressed in the second 

 conclusion at which we arrived above, that for the development 

 of new classes of cotton, in other words, the introduction of an 

 additional term into our algebraic formula. The history of the 

 Egyptian cotton-plant is a comparatively recent one, and is too well 

 known to require repetition in the pages of this report. The point 

 I desire to emphasize here is the presence of the Sea Island plant 

 at some stage of the parentage. We are at present too ignorant of 

 the " unit factors " on which the various lint characters depend 

 to state with certainty that those factors which are responsible for 

 the special spinning qualities of the Sea Island cotton are bred out 

 in their entirety. It is still possible that these exist here and there ; 

 it is even possible that they commonly exist in the present types of 

 Egyptian cotton, but are suppressed, masked, or inhibited. Under 

 the conditions of the Egyptian cotton field with the mixture of types 

 now prevalent, and with unlimited possibilities for cross-fertilization 

 between these, it would not be a matter for surprise if, now and again, 

 such combinations should occur which will permit the re-expression 

 of those characters. The sporadic occurrence of such " throw-backs ; " 

 is not unknown, and there is reason to believe that their occurrence 

 is still taking place at the present time : the history of the origin of 

 Sakel, with its superior length, is evidence in this direction. Here, 

 again, selection is the means of preserving and establishing any such 

 variations as may occur, but it is a selection which differs somewhat 

 in form from that previously referred to. The latter can be under- 

 taken within the limits of an experiment station, for what it is desired 



