128 EXPEEIMENT STATION EECOKD. 



utilizing the carbohydrates through their roots. In tlie absence of light the 

 utilization of sugars took place very slowly, ami it appears that for this form 

 of syntliesis sunlight is necessary. 



Handbook of flower pollination, P. Knuth, trans, by J. R. A. Davis (Ox- 

 ford: The Clarcnihm Press, 1006, pp. XIX+382, figs. 8i).— This voliune, vehich 

 is No. 1 of a series, is based on Miiller's work on The Fertilization of Flowers 

 by Insects, and it deals with the structure of flowers and the relation of in- 

 sects to pollination. A bibliography of more than 3,800 titles completes the 

 volume. 



Color stimulus and vital functions of plants, .1. B. Dandeno (Rpt. Mieh. 

 Acad. ScL, 7 (1905), pp. JfJf-Jfli). — A number of experiments are reported upon 

 which were carried on to determine the effects of different portions of the 

 solar spectrum on different functions of plants. Red, yellow, green, blue, and 

 violet colored glass plates were used, which gave results appi'oximatiug those 

 obtained with pure colors. The detailed results are given, which show that 

 red stimulates growth more than yellow, while yellow is more active in photo- 

 synthesis. Blue and violet exercise greater formative influences than the other 

 colors. 



A study of the effect of dilute solutions of hydrochloric acid upon the 

 radicles of corn seedlings, F. A. Loew (Rpt. Mich. Acad. ,Sct., 7 (1905), pp. 

 50-52). — The author carried on a series of experiments to ascertain the cause of 

 the death of the radicles of germinating grains of corn in extremely dilute solu- 

 tions of hydrochloric acid. Different lots were subjected to treatment with a 

 1/256 normal solution of hydrochloric acid and comparisons made with seed- 

 lings germinated under normal conditions. 



It was found that the amount of acid in dilute solutions of hydrochloric acid 

 is reduced by growing corn seedlings in them. The mineral content of radicles 

 killed in 1/256 normal hydrochloric acid was nearly one-half that of normal 

 radicles. Bacteria and fungi were found to thrive in the solution in which the 

 seedlings had been killed. Seedlings which were killed in the hydrochloric 

 acid solution mentioned above excreted mufla material rich in potash, and it 

 was found that those grown in distilled water excreted potash, or some other 

 alkali. 



The death of the radicles is believed to be caused by a chemical action, from 

 the fact that the amount of acid in solutions in which the seedlings were grown 

 became greatly reduced. The fact that the killed radicles contained less potas- 

 sium than normal ones and that the solution in which they were killed was 

 rich in potassium, suggests that death is caused by a chemical action between 

 the acid of the solution and the potassium of the radicle. The fact that fungi 

 and bacteria grew vigorously in the solution in which the seedlings were killed, 

 but did not thrive in the distilled water in which the seedlings were growing, 

 suggests that the excretions caused by the acid solution might be some organic 

 compound especially nutritious to these lower forms of plant life. 



The toxic action of copper sulphate upon certain algae in the presence of 

 foreign substances, Ei.lkn 1>. P.ac ii {h'pt. Midi. Acad. Sci.. 7 (1905). pp. ^8- 

 50). — A toxic action of copper sulphate of extreme dilution upon certain algiB 

 I'.aving been claimed, the author carried on a series of experiments to test the 

 strength required to kill some of the lower alg;v> in a<iuarium jars without being 

 injurious to the higher forms. 



The presence of foreign substances in the water was found to exercise a very 

 appreciable influence on the strength of solution required, and it appears that 

 the strength of the copper sulphate necessary to free an aquarium, from algse 

 must depend upon the percentage of plant life present, the amount of nonchem- 

 ical foreign substance in the water, and the kind of water. It seems possible 



