264 KANSAS UNIVERSITY SCIENCE BULLETIN. 



since the seed coats are readily penetrated by water, the seeds 

 germinate quickly and are not apt to live long in the soil. I 

 found that upon soaking the seeds over night, the embryos, 

 which are green, had broken the seed coats and were uncoiled. 

 Dry seeds planted under artificial garden conditions were 

 germinated and through the soil in three days. This speedy 

 germination is characteristic of the seeds of xerophytic plants. 



According to G. E. Patrick, Bulletin No. 26, Iowa Experi- 

 ment Station, the Russian thistle is richer in protein than red 

 clover; and I find, upon comparison with other data, that it 

 is as rich in protein as alfalfa. The clovers obtain most of 

 their nitrogen from the air, Avhile the thistle derives its from 

 the soil. 



The most striking anatomical feature in this species is the 

 anomalous structure of the stem. This anomaly occurs in 

 all Chenopodiaceaj in which the growth in thickness is con- 

 siderable (Solereder, 1908). It consists in the appearance of 

 pericyclic strips of cambium, which originate and lose their 

 activity successively, forming secondary bundles outward and 

 conjunctive tissue. In other members of the family the peri- 

 cyclic cambium is a continuous ring, forming concentric rings 

 of wood and phloem (Solereder, 1908). Figures 1 and 2. show 

 the anomaly in Salsola kali L. var. tenuifolia. Figure 2 is a 

 cross section of a young stem, where secondary xylem is repre- 

 sented by heavj' stippling in the vascular bundle. Figure 1 

 is a cross section of a much older stem. Here the stippled 

 sections in the vascular bundle ring indicate the masses of 

 phloem. These retain their cellulose walls, while they are sur- 

 rounded successively by xylem and prosenchymatous conjunc- 

 tive tissue with lignified walls. Figures 4 and 5 illustrate the 

 same in more detail. The root exhibits the same anomaly of 

 structure as the stem. (Fig. 3.) The same peculiarity of 

 structure is common in Amaranthacese and Nyctaginacese 

 (Solereder). 



When viewed macroscopically, the stem of Salsola kali var. 

 tenuifolia has usually eight principal longitudinal ribs more 

 prominent than the channels and lighter in color. As the 

 stem grows older these ribs and the trichomes that appear 

 upon them become red. The ribs are composed of collenchyma 

 cells with very thick cellulose walls. Figure 8 .shows these 

 cells in cross section, and figure 9 the same in longitudinal 



