

142 Wester: Carica Papaya 



the development of this plant was watched with great interest. In 

 July, 1905, the first flowers appeared. For several weeks all 

 blossoms were staminate. In August several hermaphrodite flowers 

 opened, which are rather rare in this species. By far the greater 

 number of the flowers were staminate, but as the plant grew larger, 

 quite a number of perfect flowers appeared in the axil of every 

 leaf. On examination it was found that the structure of these 

 flowers varied to a remarkable degree. Three distinct types of 

 flowers were easily recognized: (1) those resembling a pistillate 

 flower more than a staminate, large, tube one-half as long as lobes, 

 anthers inserted in the throat of corolla, ovary large, angular, 



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stigmatic end superior to anthers, ovules numerous, stigma nor- 

 mal ; (2) those with the characters of both the staminate and pis- 

 tillate flowers equally present, tube longer than in the type 

 described above, ovary not so large, one or more of the stigmatic 

 rays abortive, in some instances only a rudimentary ray being 

 present (fig. i, c and d) : (3) flowers approaching more closely a 

 staminate flower in structure than either of the two classes men- 

 tioned, having the tube and lobes of equal length, ovary small, slen- 

 der, ovules few, stigma reduced to a stigmatic area at the apex of 

 the ovary (fig. i, &), inferior to or level with the anthers. It was 

 noted also that the pollen masses were released just before or 

 about when the flowers opened where it was inferior to or on a 

 level with the anthers and in some instances, at least, where this 

 organ was superior to the anthers. 



In order to determine whether the development and formation 

 of the fruit might be correlated with the structure of the flower, a 

 series of notes was taken upon a number of flowers ail on the same 

 tree. In most instances the bisexual flower-buds were bagged 

 with small paper sacks before they opened, the sack being retained 

 until the flower had faded and the ovary was beginning to develop. 

 Numerous small black ants frequent the flowers of the papaya to 

 get the honey secreted, and to prevent a possible cross-pollination 

 by these insects a broad band of cotton was tied around the trunk 

 of the plant, which prevented their ascent. It may be mentioned 

 here that bees or other large flying insects do not seem to act as 

 fertilizing agents in this species, the pollen evidently being carried 

 by the wind, or, more probably, by small insects, from the stami- 



