646 EXPERIMENT STATION RECORD. 



The deleterious influence of free humus acids on germination is strik- 

 ingly shown by the results given in the table. The rootlets of grains 

 sown in humus soils invariably presented an abnormal appearance, 

 both as regards position, number, and shape, and the root tips appeared 

 brown, scorched, and shriveled, separated from the rootlet itself by a 

 partition. The proper treatment of humus soils includes liming, admix- 

 ture of sand, and good tillage. — f. w. woll. 



The Russian thistle, L. H. Pammel {Iowa Sta. Bui. 38, pp. 24, pis. 

 4, Jigs. 3). — The present bulletin is issued as supplementary to Bulletin 

 26 of the station (E. S. R., 0, p. 551). Since the previous bulletin was 

 issued sufficient information has accumulated on which to base some 

 opinion as to the aggressive character of the weed. The present dis- 

 tribution in Iowa embraces 48 stations; but the author thinks that on 

 account of the fact that cultivated crops are so extensively grown in 

 the State the weed will never become as noxious as many other species. 

 Notes are given on the character of the plant, its distribution, methods 

 of eradication, and its forage value, together with a partial bibliography 

 of station and department publications relative to it. 



Sixth report on Kansas weeds, A. S. Hitchcock and G. L. 

 Clothier {Kansas Sta. Bui. 80, pp. 113-164, pis. 16). — In Bulletin 57 

 of the station (E. S. R., 8, p. 409) the authors give a descriptive list 

 with distribution of the weeds of the State, but since that time many 

 notes and observations have accumulated and it is thought desirable to 

 issue a new bulletin showing the distribution of weeds throughout the 

 State. As in the previous bulletin, the distribution of the different 

 species is indicated by maps in which a dot indicates the presence of an 

 authentic specimen from the different counties of the State. In the 

 present bulletin 209 species are described, 80 of which are included in 

 the list designated as bad weeds. While other species than those 

 enumerated may be troublesome in some localities, yet from several 

 years experience it is thought that for the State as a whole the list 

 would be confined to the species enumerated. Of the 80 bad weeds 23 

 are perennial, 7 biennial, and the remainder annuals, several of which 

 are so-called winter aunuals. Of the total list of weeds enumerated 

 149 species are native to the State, and of the list of bad weeds one-half 

 are native plants, and among these are many of the worst. The distri- 

 bution throughout the United States of the 80 weeds classed as most 

 troublesome is also given. 



The methods by which weed seeds are scattered are discussed at some 

 length, the principal agents mentioned being wind, animals, automatic 

 movements, railroads, and the use of impure grass, grain, and vegetable 

 seeds, etc. 



In 1893 a plat 10 ft. square was marked off on the station ground 

 and a record kept of the seedling weeds which were removed from time 

 to time. This has been continued for several years and the record for 

 1893-1897 is given. 



