106 



of exceedingly tough, coarse strands, which will stand a considerable 

 amount of strain, attaching the nut to the husk. Neither of these 

 specialized fibres was to be found in the sterile nut. A microscopical 

 examination disclosed no important differences in the bast cells which 

 make up any of the strands of either the perfect or the abnormal husk. 

 The difference in the relative thickness and stiffness seems entirely due 

 to the number of cells in a strand. 



In order to determine just what proportion nut and husk had in 

 the normal fruit, the nut was removed and the husk weighed. It was 

 found to weigh exactly half of the original amount, or 400 grams. 

 The other fruit, which was approximately the same size, weighed, as 

 noted above, 575 grams, the average of fresh specimens being about 

 610 gramg. So that it would seem as if some of the substance which 

 would usually go to the formation of seed was here devoted to increas- 

 ing the bulk of husk. 



Since no trace of fungus, insect, or bacterial activity could be found, 

 no direct evidence as to the cause of the condition of the defective fruits 

 could be produced. The probability is, however, that the responsibi- 

 lity for this state of the fruiting organs is to be laid to none of these 

 agents, but is the result of the failure on the part of the flower to 

 effect pollination. Such failure seems to be more or less common and 

 well known, as is evident from the following statement from the 

 Cyclopedia of American Horticulture (L. H. Bailey Vol. 1. p. 342 :) 

 Coco-nuts, like many other fruits, often grow to a considerable size 

 without pollination, and then perish." 



An examination of the pistils and stamens of the trees, producing 

 these fruits with regard to the method of pollination would probably 

 afford an explanation of the absence of seed in the specimens under 

 consideration. 



A diagram showing the relative extent of the tissues in the two 

 fruits is appended. 



E. M. Kupfer. 



Explanation of Figures : A. Normal, B. Sterile Fruit : 



a. husk fibres ; b. shell ; c. endosperm ; d. finer fibres around micropyle ; 



e. embryo. 



a- 

 b- 



