128 Journal of the Department of Agriculture. 



2. — A Physiological Tkouble. 



Plants, like animals, are subject to constitutional derangements 

 brought on by external influences and conditions of growth. One 

 such derangement in sugar-cane is the occurrence in the inteinodes 

 of strips of spongy tissue or cavities surrounded by spongy tissue 

 mg 5). 



This condition is also recorded from Java, and is t'ouiid in cane 

 in which for some reason the growth has been irregular, such as a 

 set back followed by a subsequent rapid growth. 



The cells in the spongy tissue are dead, filled with air, and na 

 suciose can collect in them. It is hence readily evident that a stalk 

 composed largely of this tissue has less sucrose than a normal stalk- 

 Such spongy stalks readily fall a prey to the attacks of fungi. 



3. — The Non-Setttnc; or Seed in Uba and Other Cane Varieties 



IN South Africa. 



Not long ago I listened to a most interesting lecture, when the 

 full details for cross-pollinating the flowers of cane were minutely 

 described, and the desirability of raising seeds of cane here were 

 carefully entered into. Unfortunately with our present knowledge 

 not much success can be expected in this direction with the varieties 

 which have arrowed here. The reason is evident when the anthers 

 and pollen of the Uba or some of our other varieties are examined. 

 It can be summarized as follows: — 



(1) The anthers appear to have lost the power to open, and 



such pollen as they may contain is not liberated. 



(2) The pollen is remarkably scanty in the anthers. 



(3) vSuch pollen as is present differs from normal pollen in the 



following aspects, which lead to the conclusion that tliey 

 are sterile : — 



(a) The pollen grains are irregular in si/e (norinal pollen 

 of cane is circular). 



(6) The pollen grains are devoid of starch ajid, compared 

 with normal grains, appear like empty shells (normal 

 pollen of cane is rich in starch). 



Until such time as we procure a variety with normal, viable 

 pollen not much success (if any) can be expected from attempts at 

 either cross-pollinating or selling. 



It will be evident that making a microscopic examination of the 

 flowers of any cane variety, with the object of determining whether 

 the essential parts are fertile or sterile, is essential before the variety 

 is used for attempts at seed production. Such an examination will 

 give an idea of the degree of success that may be expected and will 

 save much time. 



