Astronomy. 173 



4. On the Ascent of colored liquids in living plants. — In Bot. 

 Zeit., May 30, Wieler calls attention to an article by Goppels- 

 roeder, which has not yet come directly under our hands. 

 From Wieler's notice, it appears that a very large number of 

 coal-tar colors can pass into the plants observed, provided the 

 solutions are very dilute. Experiments in this direction were 

 conducted in the Botanical Laboratory of Harvard College dur- 

 ing the past winter, by two students, whose work is nearly ready 

 for publication. From their studies it is plain that there is a 

 wide difference in the power of different plants to absorb these 

 solutions, and there are also very great differences as regards the 

 absoi*ption of different colors by any single plant. In some in- 

 stances it has been possible to replace one color by another, pro- 

 vided the roots remain sound. Those cultures succeeded best in. 

 which the solutions were kept very slightly acid, as was naturally 

 to be expected. The distribution of color in the tissues of the 

 plants experimented on was very different, even in the same 

 species. It has been impossible to resist the conclusion that in 

 nearly every case the employment of the liquid introduced a dis- 

 turbing factor, the effects of this disturbance being diverse. In 

 the case of seedlings the plants were prone to yield to attacks of 

 moulds, and speedily decay. Experimenters must keep in mind 

 the fact that colored solutions are easily absorbed through in- 

 jured roots, and, further, that plants with injured roots can live 

 and grow slowly for a considerable time. G. l. g. 



5. Analytical Key to the Genera and Species of North Amer- 

 ican Mosses ; by Professor C. F. Barnes, Madison, Wise. 

 Pamphlet. — This most useful work is distinguished by its sharp 

 lines of definition. In the few cases in which we have put it to 

 a practical test it has made short work of difficulties. It supple- 

 ments admirably the treatise of Lesquereux and James, g. l. g. 



6. Structural and Systematic Botany / by Professer D. H. 

 Campbell. Ginn & Co., Boston, 8vo, 253 pp. The author has 

 taken for his work the title which Dr. Gray gave to his compre- 

 hensive treatise very many years ago, and which survives as a 

 minor title even in the sixth edition. A cursory reading im- 

 presses us favorably, leading us to believe that the work will be 

 useful in the hands of judicious teachers, and in much the 

 same way as the excellent treatise by Professor Bessey. With 

 these two works and the plain practical Plant-Dissection by 

 Professors Arthur, Barnes and Coulter, botanical students are 

 likely to have enough guidance of the right character. The ad- 

 vice in any and all of the foregoing handbooks is sound and safe, 

 and it ought to do very much toward turning out a large num- 

 ber of earnest workers. G. l. g. 



IY. ASTEONOMY. 



1. On the Spectrum of the Nebula in Orion ; by William 

 Huggins and Mrs. Huggins. — A new study of the spectrum of 

 the nebula of Orion, with improved instruments and instrumental 



