432 EXPEEIMENT STATION EECOED. 



It appears that calcium did not favor tlie development of A. niger, or at least, 

 if it did, it was when it was present in such small quantity as not to be recog- 

 nized by the methods adopted. Calcium was fixed completely when present in 

 small quantity in solution, and partially when the strength of solution was 

 greater. The increase in weight under these conditions is taken simply as a 

 result of the increase in the amount of calcium in the ash. 



On the presence of barium in the ash and extract of certain Kansas weeds, 

 E. H. S. Bailey and L. E. Sayre (Trans. Kans. Acad. Sci., 23-24 (1909-10), 

 pp. 194-198). — On account of the suggested relation of barium to certain dis- 

 eases, a study has been made of the ash and extract of a number of species of 

 plants to determine the presence of barium, manganese, magnesium, and other 

 constituents. 



Of 16 species of common weeds, barium was found in elder, ragweed, Aplo- 

 pappiis ciliatus, Oxytropis lamberti, and agrimony. 



Some laboratory experiments are reported, in which the effect of barium in an 

 extract of Astragalus upon guinea pigs was studied. These seem to indicate 

 that while barium may be a factor in producing disease, there is another prin- 

 ciple in the Astragalus that acts as a poison. 



The effect of tarring roads on the growth, of trees in the Bois de Boulogne, 

 C. L. Gatin (Compt. Rend. Acad. Sci. [Paris], 153 (1911), No. 3, pp. 202- 

 204). — ^An account is given of observations made upon catalpa (Catalpa higno- 

 nioides) and 2 forms of Robinia pseudo-acacia, in which studies were made 

 of the leaves of these trees along roads that had been given coatings of tar and 

 along those which had not. In nearly every instance it was found that the 

 normal plants had a much greater leaf development than where they had been 

 subjected to the vapor and dust from tarred roads. 



The author proposes an experimental investigation on the effect of the dust 

 and vapor from oiled or tarred roads on plants. 



The experimental reproduction of the injury to plants by the vapors and 

 dust arising from tarred roads, C. L. Gatin (Compt. Ren4. Acad. Sci. [Paris], 

 153 (1911), No. 15, i)p. 688-690).— In continuation of the above studies, the 

 author covered the leaves of maple, lilac, walnut, ash, red currant, rose, and 

 others with the dust such as arises from tarred roads, applying it once a week 

 from July 1 to IS, and afterwards 2 or 3 times a week until the middle of Sep- 

 tember. 



All the plants showed the effect of the application, the leaves of the ash and 

 the walnut being burned, while the young leaves of the maple were scorched 

 and perforated and the old ones were tux*ned brown. The effect of the treat- 

 ment on the rose, in reducing the length of the leaves and the number and size 

 of the leaflets, is also shown. 



Anatomical modifications produced on plants by dust from tarred roads, 

 C. L. Gatin and Fluteaux (Compt. Rend. Acad. Sci. [Paris], 153 (1911), No. 

 21, pp. 1020, 1021). — Studies were made in July and in October of leaves and 

 branches of catalpa and 2 forms of locust, in which it was found that the 

 plants which had been submitted during the season to dust from tarred roads 

 had become considerably modified. The leaves were reduced in size, the 

 parenchyma very much changed, the axial cylinder modified, and in the 

 branches the medullai-y rays were greatly reduced. Plants under certain con- 

 ditions seemed to protect themselves against the injurious action of the dust 

 by the development of suberized tissue. The action of the dust on trees is a 

 gradual one, and in the case of catalpa it was found to result in the complete 

 removal of reserve starch. 



Floral anomalies in Japanese hops and hemp due to early seeding, J. 

 TouRNOis (Compt. Rend. Acad. Sci. [Paris], 153 (1911), No. 21, pp. 1017- 



