POLLINATION OP THE MANGO. 3 



of these characteristics ; it produces comparatively few pollen grains, 

 often not more than 200 in an anther, and never more than 1,200 

 in any that were examined; and it must be remembered that this 

 represents the total number produced by one flower, since there is 

 commonly but one fertile stamen. The pollen grains show a decided 

 tendency to cling together, especially in damp weather; and even 

 on bright, sunny days it was found difficult to dislodge them from 

 the anther by subjecting them to the full draft of an electric fan for 

 30 minutes, most of the grains still clinging to the anther at the 

 end of that time. The stigma is exceedingly small and not pro- 

 vided with projections of any sort to assist in catching pollen. 



On the other hand, the production of honey for the attraction of 

 insects shows a distinct adaptation to insect pollination. The 

 structure of the flower is such as to entitle it, apparently, to be 

 placed in Miiller's biological class "A", or "flowers with freely 

 exposed honey." 1 Flowers of this class are visited by insects of 

 several orders, from the short-tongued Coleoptera to the long- 

 tongued Lepidoptera, and members of both these orders, as well 

 as of Diptera and Hymenoptera, have been observed on mango 

 flowers, as will be described later on. 



STRUCTURE OF THE FLOWER. 



The mango is polygamous and produces its flowers on terminal 

 panicles varying in length from a few inches up to 2 feet, each panicle 

 carrying from 200 or 300 up to more than 4,000 flowers, of which 

 only 2 or 3 per cent are perfect in some instances ; in others as many 

 as 60 or 75 per cent. (PL I.) The character of the panicle and 

 the number of flowers produced upon it vary with different varieties, 

 as also the length of time they remain in bloom. Some varieties re- 

 main in flower but 10 days, others for nearly 2 months, and on one 

 panicle of the Sandersha 4,200 flowers were counted which opened 

 at the rate of 20 to 240 a day, extending over a period of 40 days. 



The individual flower 2 is subsessile, 6 to 8 millimeters in diameter 

 when the corolla is outspread, the calyx composed of five ovate- 

 lanceolate, finely pubescent, concave sepals and the corolla of five 

 elliptic lanceolate to obovate-lanceolate petals, 3 to 4 millimeters 

 long, whitish, with three or four fleshy orange ridges toward the 

 base, and inserted at the base of a fleshy, almost hemispherical 

 disk, obscurely 5-lobed and usually about 2 millimeters in diameter. 

 In the perfect flower the disk is surmounted by a globose-oblique 



!Muller, Hermann. Alpenblumen . . . p. 485. Leipzig, 1881. 



Knuth, P. E. O. W. Handbook of Flower Pollination ... v. 1, p. 64. Oxford, 1906. 



2 The structure and development of the mango flower have been briefly discussed by Burns and Prayag. 

 (Burns, W., and Prayag, S. H. Notes on the inflorescence and flowers of the mango tree. In Poona 

 Agr. Col. Mag., March, 1911.) 



