236 SEXUALITY [BOOK n. 



pollen animalcules (saamenthierchens) ; and in these cases 

 the contents of the pollen, quoad solida, also for the greatest 

 part consist of starch. I have, at least, in (En. Simsiana, 

 grandiflora, and crassipes, throughout, found nothing else in 

 the pollen besides a solution of gum and those easily recog- 

 nisable small crescent-formed bodies, which Brongniart has 

 described as pollen animalcules. They are, however, decidedly 

 starch, and continue starch even when the pollen tube is 

 already deep in the nucleus of the ovule. In order, however, 

 in this case, to detect the starch, we must employ the aqueous 

 solution of iodine, for the alcoholic solution in the first place 

 would coagulate the gum, and in the second it colours the 

 starch so deeply that, on account of the smallness of the 

 grains, one can no longer judge of their colour, and as they 

 are entirely surrounded with the gum, they may easily be 

 supposed to be dark brown. The curvilinear motions of these 

 so called pollen animalcules, which are said to have been 

 observed by a good many, are very easily explained, since at 

 least many of them, being crescent-shaped, when in motion, 

 appear bent to the left, the right, or appear straight, accord- 

 ing to their position to the eye." 



With respect to the sexuality of plants, that at least would 

 appear, from the facts above recited, to be established beyond 

 controversy ; but lately there has arisen in Germany a school 

 of Botanists, at the head of which are Schleiden and Endli- 

 cher, who either deny it, or assert that the nature of the 

 phenomenon connected with it has been misunderstood. 



Schleiden states that, " if the pollen tubes be followed into 

 the ovule, the most delicate process perhaps that occurs in 

 botanical investigations, it will be found that usually only 

 one, rarely a greater number, penetrates the intercellular 

 passages of the nucleus and reaches the embryo-sac, which 

 being forced forwards, is pressed, indented, and becomes the 

 cylindrical bag which constitutes the embryo in the first 

 stage of its development, and which consequently consists 

 solely of a cell of parenchyma supported upon the summit of 

 the axis. This bag is therefore formed of a double membrane 

 (except the open radicular end), viz. the indented embryo-sac 



