528 EXPERIMENT STATION KECORD. 



some of this injury. The most practicable means are T)elieved to l)e the erection of 

 tall smoke stacks or chimneys in order to secure the most effectual aid in rapid dilu- 

 tion of the gases; or, if possible, the location of such works in large open plains, 

 instead of in ravines or valleys, as is usually the case. 



Action of carbon bisulpliid on the growth of trees, E. Henky {Bill. Soc. 

 Sci. Nmunj, 3. ser., 2 {1901), No. 1, pp. £7-33). — The stimulating action of carbon 

 bisulphid upon the growth of various plants and the results of exi^eriments in 

 which soil abf)ut locust trees was injected with carbcm bisulphid at the rate of 400 

 cc. per square meter are shown. The effect <jf the treatment was soon apparent, and 

 at the end of 2 years the difference in 2 lots was very evident, the treated lot weigh- 

 ing nearly 3 times as much as those not treated. 



The factors which influence the size, number, location, and action of the 

 root tubercles of leguminous plants, L. Hiltner {Arh. K. (Jenundheitsamte, Biol. 

 AbL, 1 {1900), No. 2, pp. 177-222, pi. 1; abs. in Mitt. Deut. Landw. GeselL, 15 {1900), 

 No. 45, pp. 268-270; Bat. Centbl., 85 {1901), No. 6, pp. 179-183; Centbl. Bakt. u. Par., 2. 

 AbL, 7 {1901), No. 5-6, pp. 202-204). — A critical review is given of the literature 

 relating to the subject of the occurrence and function of bacteria in the root tuber- 

 cles of leguminous plants, and extensive experiments are reported in which the 

 author investigated the effect of various factors on tubercle development. It is 

 claimed that the quantity of inoculation material does not exercise an appreciable 

 effect upon the number, size, or activity of the tubercles. The projiortion l)etween 

 the total development of tubercles and the development of aerial parts of plants is 

 about constant when the other factors, aside from the inoculation material, are the 

 same. This statement applies only where bacteria of similar virulence are employed. 

 When races of root tubercle bacilli of low virulence are compared with more active 

 ones, the greater activity is always with those of the higher degree of virulence. 

 This, accordhig to the author, determines the size, number, location, and action of 

 the root tubercles upon leguminous plants. Active tul^ercles upon the roots produce 

 in a plant a sort of immunity against other bacteria of equal or lower virulence, and 

 such plants can be stimulated to greater tubercle development only by the use of 

 more powerful inoculation material. 



The character of the soil, as influencing tubercle development, is discussed and 

 the dependence between poor soil and abundant tubercle development is again 

 pointed out. Where an abundance of availalile nitrogen is present, extensive root 

 tubercle development is not to be expected. The effect of moisture in the air and 

 soil, as factors in the distribution and development of root tubercles, is also discussed. 



Physiological studies with reference to the germination of certain fun- 

 gus spores, B. M. Di-ggar {Bot. Gaz., 31 [1901), No. 1, ]/j>. 3S-66}. — A report is 

 given of investigations to ascertain the influence of certain special factors on 

 germination. Most of the experiments' were made with hanging drop-cultures, 

 and comparisons made with spores grown in a standard nutrient solution. The 

 percentage of germination of the spores of about 20 species of fungi is given. 

 The effect of certain stimuli on the germination of spores was investigated, spores of 

 Aspergillus favus, Sferic/matocystis nigra, and Phycomyces being treated with various 

 carbon compounds, metallic salts, and mineral acids. In many instances a decided 

 stimulus was given the germination, while in others the stimulus, if any was pro- 

 duced, was slight. The influence of evaporation, surface tension, and other physical 

 agents on spores was investigated, as well as the inhibiting action of various nutrient 

 solutions. The resting stages and drying of spores was a sul^ject of investigation, 

 in which it was determined that the spores of certain fungi have an apparent resting 

 stage, the germination of some increasing considerably from summer to autumn. 

 Spores of sonie fungi kept dry in the laboratory for 5 years gave no germination, 

 while material 1 and 2 years old germinated reavli'y in nutrient media. The effect of 

 dilution of food materials on germination was examined, and it was found that a ten- 



