156 Proceedings of luO'iuiia Academy of Science. 



below this strength of the sugar solution the pollen grew. The second 

 point of interest is that the branching of the pollen tube which this plant 

 showed occurred only in the 30% of cane sugar and as above noted. It will 

 be seen that in 40% cane sugar the germination dropped ofe greatly as 

 only 3 grains of pollen grew. It has been known for a long time that the 

 pollen tube sometimes branches as it descends through the stigma of some 

 plants. The germination of the pollen of this plant was rather slow as it 

 required one-half an hour to begin. Its pollen lived in the ungerminated 

 condition for eight days and it grew best in a 20% solution of the cane 

 sugar. Most of the pollen experimented with in the cultures used in this 

 investigation was from plants gathered in Monroe County, Indiana. Some 

 of the plants were obtained from widely separated localities and where- 

 ever and whenever an opportunity presented itself. Some came, for ex- 

 ample, from Texas, some from INIissouri, and others from Colorado which 

 I gathered on Pike's Peak and vicinity. Twelve plants from Pike's Peak 

 that I tested especially as regards their longevity, lived only ten days in 

 the longest case. Some of these I did not expect would germinate under 

 any conditions, whether their pollen was young or old, and this was fully 

 verified by experiment. However, these plants were in every case also 

 subjected to the usual investigation in order to leave no doubt on the ques- 

 tion. Still others of the plants came from Dearborn County and from 

 Clark County, Indiana. All of the experiments in this paper were carried 

 out, as above stated, in pure distilled water and in the different strengths 

 of cane sugar mentioned. The distilled water and cane sugar were as pure 

 as possible. No experiments were performed or attention given to the 

 question of additional siibstances, such as gelatine, added to these solu- 

 tions. Considerable work also has been done in some phases of this field. 

 It constitutes, however, a problem in itself and merits much more extended 

 investigation than it has yet received. 



