342 



mouths of which wore previously dipped in water to allow them to 

 be drawn tightly round the base of the panicles and tied tightly 

 with raffia to prevent the ingress of insects. 



The stigma became receptive very shortly after the natural 

 opening of the flower. This receptive condition of the stigma 

 was indicated by its turning slightly darker than the style and 

 appearing roughened on its surface ; this can only be seen with 

 the assistance of a strong lens. . 



A few ripe anthers were then chosen from Ceylon No. 1 and 

 gently crushed on a watch glass. The pollen was then trans- 

 ferred to the stigma by a small scalpel made by hammering out 

 the small end of a pin. This method was chosen in ])reference 

 to the use of a camel-hair brush, as the amount of pollen obtainable 

 in the case of the mango is very small and would possibly be lost 

 in the hairs of the brush. 



When the stigma had been successfully covered with the pollen 

 the paper bags were quickly replaced. These were allowed to re- 

 main for several days, until the ovary commenced to swell : thev 

 were then removed and replaced by fine muslin bags. In all 145 

 flowers were operated upon as described. This extended over a 

 period of two months. 



On the ninth day from emasculation, the bags were removed 

 in each case and the flowers examined. It was then found that 

 the majority of them had been shed and only a total of twentv- 

 four out of the 145 commenced to swell. 



The swelling of the ovary is. I believe, commonly regarded as 

 a sign that successful fertilization has taken place. In the present 

 case, however, thirteen of these ovaries ceased to develop and 

 finally withered after having doubled their normal size. This 

 swelling was probably due to some irritatiiMi licing caused bv the 

 growth of the pollen tubes. 



Eleven fruits continued to dcvelo]). but untdrtnnately very 

 strong winds set in and destroved seven of the most i)ri)mising 

 when they were al^out half developed. With great care four fully 

 develoj^ed fruits were ol)tained but only two were successfully 

 germinated. 



Complications due to poivemI)r\i>n\- had been aiuicipaled, ])ut 

 f^mly a single seedling developed in each case. 



Experiments arc in i)rogress. the results of which are hoped 

 to further our knowledge in solving this i-)roblem of the jiolycm- 

 liryony ol the mango. Tn the absence of information to the con- 

 trary, it would have been assumed — had it been necessary — that 

 the strongest of the seedlings was the "normal." believing it t<i 

 have been the result of the fertilization of the egg-cell. 



The two i)lants obtained have been planted out and are making 

 good growth. When thev have developed sufficiently, steps will 

 be taken to induce earl\- fruiting ^n tliat thi< work can be cu'ried" 

 on to its final issue. 



