628 EXPERIMENT STATION RECORD. [Vol 40 



or on the percentage of bolls to flowers. Considerably larger yields were ob- 

 tained from two plants per hill than from one plant, while no effect on the 

 percentage of bolls to flowers from spacing was observed. Further study of 

 the effects of spacing on Sea Island cotton is emphasized. 



The author concludes that " it has been shown clearly that, under the con- 

 ditions under which the experiments were carried out, there is a striking 

 uniformity in the time at which flowering begins, reaches its maximum, and 

 declines to zero. If the sowing date be known, we can state with certainty 

 when most flowers and bolls will be produced and when the crop will be 

 finished. We can not predict what the size of the crop will be further than 

 by stating its probable maximum. The size of the crop depends on 

 weather conditions, and on the Incidence of fungoid disease. Thus, in the 

 West Indies, or indeed in any country where cotton depends for its water 

 supply on rainfall and not on irrigation, the value of flowering records is 

 very much less than in Egypt. The Egyptian boiling curve is of less ampli- 

 tude than the flowering curve, chiefly through shedding. The percentage of 

 shedding is said to be practically constant at 40 per cent. In nonlrrigated 

 countries the boiling curve represents the bolls left after shedding and disease 

 have taken their toll, and we have seen that the percentage of bolls to 

 flowers fluctuates greatly from season to season. 



" For manurlal and spacing experiments in the West Indies, it is probably 

 sufficient to take boiling records only, at weekly intervals. . . . For the 

 comparison of different varieties in regard to yielding capacity, both flowering 

 and boiling records are almost essential. It is certain that considerable dif- 

 ferences exist in Sea Island cotton in respect to the liability to shed bolls. 

 These differences could be brought out adequately only by a careful study of 

 the flowering and boiling records." 



The maintenance of the quality of Egyptian cotton, G. C. Dv/dgeon (Bui. 

 Imp. Inst. [So. Kensi7Ujton], 16 (1918), No. 2, pp. 160-170).— The author dis- 

 cusses the importance and the factors involved in the maintenance of valuable 

 strains of cotton in Egypt. The necessity for cooperation among growers and 

 ginners, with Government assistance if necessary, in maintaining the purity of 

 desirable types is emphasized. He concludes that " the period of life of an 

 Egyptian commercial variety is not long, owing to the fact that the character- 

 istic qualities which constitute its value are usually rapidly broken down by 

 cross-fertilization in the field and by careless mixture of seed in the ginneries. 



"The origin of all Egyptian commercial varieties appears to have been a 

 single plant in each case. These plants may be assumed to have been ' mutant ' 

 strains, the nature of which, so long as they are each inbred, is to breed true 

 to the parent type. The theory of the commercial varieties being ever-splitting 

 hybrids is therefore apparently untenable. The assumption of the mutational 

 origin of Egyptian commercial varieties is supported by what has been found 

 to occur in experimental breeding from Egyptian seed in Arizona." 



Egyptian commercial cottons, G. C. DUDGEON (Mill. Ayr. Egypt, Tech. and 

 Sd. Serv. Spec Bui., 1918, pp. 11). — This comprises a brief discussion on the 

 advisability of making provisions for maintaining the purity of the different 

 strains of Egyptian cotton in Egypt through Government supervision, together 

 with notes on the origin of commercial varieties and on the means of preserv- 

 ing their individuality. 



An old treatise on hemp, W. H. Boomgaakd (Cultura, 30 (19 18), Xo. 

 360, pp. 232-238, fig. 1).— The author presents an early account of hemp <r,;>i- 

 nabis sativa) including a description of the plant and the preparation of the 

 fiber and its uses. 



