Leake and ram prasad. 69 



From the observations just recorded it would appear that in 

 the United Provinces such cross-fertihsation as occurs is the work 

 of some insect with a limited range of flight. Of the two insects 

 most commonly observed at the cotton flower one is a small bee 

 Apis florea Fabr.* Towards sunset this bee is to be found in the 

 partially withered flowers, in which it appears to spend the night, 

 to issue on the following morning densely coated with pollen. It 

 is possible that some of this pollen may still be adhering when the 

 flowers first open and undoubtedly pollen then deposited on the stig- 

 ma is most likely to cause fertilisation, for the anthers are at the time 

 still complete. On the other hand, the period between dawn and 

 the opening of the flower is considerable, and in this period the insect 

 which is strong on the wing would have covered a considerable dis- 

 tance. If the conclusions drawn as to the distance at which cross- 

 fertilisation takes place be correct, it would appear more probable 

 that, by the time the flower opens the insects have freed themselves 

 from adherent pollen and therefore are rarely, or never, the agents 

 of cross-fertilisation. 



The second insect commonly met with on the cotton flower is 

 a small beetle, CarfOfhilus dimidiatus Fabr. The range of this 

 beetle is undoubtedly limited and frequently numbers are to be found 

 crawling inside a single flower. In their actions they may be 

 described as clumsy, frequently falling from one portion of the flower 

 to another and in so doing they become densely coated with pollen. 

 They may, moreover, frequently be seen in the morning, having left 

 the withered flowers of the day before, entering the unopened or 

 opening flower by forcing their way between the spirally wound 

 petals. Though a great deal of the pollen is, no doubt, dislodged 

 during the process there seems every possibility that a certain 

 amount may be still adhering when the insect gains the interior of 

 the flower, and if it is then deposited on the stigma, cross-fertilisa- 

 tion is almost sure to occur. 



* For the itlentification of these insects I am indebted lo Mr. H. Maxwell-Lefrr.y, 

 Imperial Entomologist. 



