PLANT HYBRIDIZATION BEFORE MENDEL 75 



relates that he had simply sprinkled the pollen over the flowers 

 without more ado. On this third occasion, he pollinated the pistil- 

 late flowers with a camel's-hair brush and, as he states, he did not 

 omit a flower. At the end of the seventh month, the large cluster 

 fertilized produced ripe and perfect fruits, those of the first 

 flowers being the largest, the later ones being of different sizes, 

 by reason of the diminishing amount of light and heat from the 

 sun. The form gf the fruits is described as resembling olives, and 

 their color, nut-brown, and in the best specimens, chestnut-brown. 

 The outer coat of the fruit is described as being fine and very 

 brilliant, the interior thick, filamentous and grayish. Under this 

 was the fleshy soft envelope of the seed, which is described as 

 having the color of fresh mace. The odor of the flesh of the fruits 

 is described as disagreeable, resembling at maturity the odor of 

 old butter, whence the name in Germany "Butter-palm." The taste 

 of the fruits is stated to be sharp, corresponding, in certain re- 

 spects, to the odor. As the result of his experiment, Gleditsch con- 

 cludes that : 



"The action which is required to produce a rather considerable change 

 has not taken and does not take place without an actual contact, imme- 

 diate or mediate, of the two palms, as is required in male and female 

 animals, conformably with the general laws of nature, and with the 

 manifest testimony of experience. The contact takes place in fact in 

 plants, but, so far as we are informed at present, the sole way consists 

 in the powder of the flowers of the male plant, where, following the 

 distinct idea which science can furnish us, is found contained that which 

 serves for the fecundation of the plant." (p. 13.) 



It is important to note that at no time does Gleditsch appear to 

 have had a clear idea as to the manner of the germination of the 

 pollen grains. The substance in their interior, he says : 



"when it is perfected, and when its time for escaping has arrived, does 

 so little by little, without the vesicles breaking for this effect." (p. 15.) 



The character of the contents of the pollen grains is taken to 

 be of the nature of an oil, since, on macerating a quantity of pine 

 pollen in a mortar with mercury, he obtained a substance resem- 

 bling wax, which could be kneaded between the fingers, but which 

 was not quite wax, he says, for, when placed in an envelope of 

 paper, it was found that "it penetrates all the paper with its 

 subtle oil." 



This oil is apparently, in Gleditsch's mind, the material agent 

 of fertilization. The pollen grains fall upon the stigma, which is 



