604 



SUGAR-CANE 



West Indies, Hawaii. The making of definite crosses 

 was first successful, it is thought, in the West 

 Indies. The greatest amount of this work has thus 

 far been accomplished in the West Indies, although 







Fig. 830. Harvestmg the cane crop. Hawaii. 



it has now begun in Hawaii and elsewhere. The 

 following facts have been slowly developed : 



The number of fertile seeds produced in a panicle 

 of cane is relatively small, as is the case with 

 many other grasses. The germinating power is very 

 transient, being at a maximum a few days after 

 ripening and rapidly decreasing thereafter so that 

 at the end of a few weeks it is often wholly lost. 

 An examination of the seeds of cane discloses the 

 fact that a large proportion of them are shrunken, 

 and this seems to indicate that a large proportion 

 of them are not fertilized. Nearly all the plump 

 seeds germinate when they are a few days old if 

 they are soaked in water for 12 hours and placed in 

 a saturated air of 100° Pahr. These are probably the 

 properly fertilized seeds. It is rare for certain vari- 

 eties to produce fertile seed ; in fact, a large num- 

 ber of varieties are not yet known to produce them, 

 though this may be due to insufficient observa- 

 tion. On the other hand, it has been established 

 by observation that the pollen of certain varieties 

 is incapable of germination and therefore of prop- 

 erly fertilizing the ovaries. This fact is deter- 

 mined by the structure of the pollen, and by the 

 fact that it will fail to develop when given the 

 proper conditions. In some instances the anthers 

 appear never to ripen properly, as they are thin, 

 off color, and never open at all. On other occasions 

 they appear to contain pollen mother-cells only, the 

 growth appearing to be arrested at that stage. 

 Attempts to secure fertile seed with such anthers 

 end in failure. It is possible that the method of 

 propagating cane solely by means of cuttings has 

 ended in a deterioration of the seed - producing 

 powers, and that perseverance in the effort to 

 secure successive generations of seedlings may 

 resuscitate this power. It is to be hoped that this 

 is the case, as it is some of the very best varieties 

 that have apparently failed hitherto to produce 

 good seed. 



Thus far three methods have been used in the 

 production of seedlings : First, seed has been har- 



SUGAR-CANE 



vested in a haphazard way from varieties that it 

 was desired to propagate This method has pro- 

 duced a large number of seedlings whose parent- 

 age pollen is unknown. Second, an attempt has 

 been made artifically to fertilize certain pani- 

 cles by giving them an excess of pollen of a given 

 kind, such as by placing near them, at the proper 

 time, panicles of other plants, either by removing 

 these latter from distant canes or by previously 

 having planted the canes near by. This has re- 

 sulted in the production of a considerable number 

 of seedlings, whose parentage pollen is uncertain, 

 but less so than by the first method. Third, by emas- 

 culating definite blossoms before the ripening of 

 their pollen, and by supplying fertile pollen of 

 another sort at the proper time. Owing to the diffi- 

 culty of accomplishing this the number of such 

 seedlings has thus far been limited to a few hun- 

 dred. By far the greater proportion of these have 

 been produced in the West Indies, notably at the 

 experiment station of Harvard University, where 

 it is said that several hundred such crosses have 

 been made. 



The third method is the only scientific one, and it 

 is probable that the difficulties will be so much les- 

 sened by experience that it will soon be possible 

 to produce crosses of definite parentage with ease. 

 As such can then be repeated at will, a definite 

 knowledge of cane pedigrees can be established. 

 This will lead to accuracy in the breeding of new 

 varieties. It is probable that the rapidity of our 



Fig. 831. Sugar-cane at harvest time. Louisiana. 



progress in this direction will be in proportion to 

 the accuracy of our knowledge of pedigree, as is 

 the case with other species. 



With regard to the improvement of present 

 varieties by these methods, there can be no doubt 



