AGEICULTUEAL BOTANY. 72 ( 



Experiments were carried on with the spores of a number of ferns to study their 

 germhiation. 



It was found that under ordinary conditions they would not germinate in 

 darkness when sown upon leaf mold. The germination was best in a medium 

 light intensity. The intensity of light was found to affect the forms of pro- 

 thallia, weak light producing tilamentous ones, while strong light produced 

 the normal forms. Weak light was found to inhilnt the production of arche- 

 gonia and favor the production of antheridia. 



The action of colored light on plants, C. Flammarion {Bill. Mens. Off. 

 Rcnsciij. Aur. \l'arh]. (; (1907). Xo. IJ, pp. 1321-1323, fig. i).— In previous 

 papers (E. S. R., Iti, p. 848) the author has given an account of the effect of 

 different colored lights on the growth of a number of plants, such as sensitive 

 plants, coleus, lettuce, gladiolus, etc., in which the most pronounced growth was 

 made under the red screens. In the present paper he reports upon experiments 

 on the growth of oaks, ferns, and beans. The greatest amount of gi'owth was 

 made under the red screens, followed by blue, white, and green in the order 

 enumerated. 



In connection with these investigations the author studied the nitrogen con- 

 tent of beans grown under the different colored lights. The greatest increase in 

 nitrogen was under the uncolored screen, and always where the conditions were 

 least favorable for chloroiihyll development. 



On the importance of physiologically balanced solutions for plants, W. .T. V. 

 OsTERHouT {B(jt. Gaz., Jt2 {1906), Xo. 2, pp. 127-13J,; J,k {1907), No. .',, pp. 

 259-212, figs. 7). — Studies were made of marine, fresh-w^ater, and terrestrial 

 plants grown in dilute solutions of natural and artificial sea water and in solu- 

 tions of sodium chlorid, magnesium chlorid, magnesium sulphite, potassium 

 chlorid, and calcium chlorid, the compounds used in making up the artificial sea 

 water. 



The results ol)tained are in striking agreement, and tend to show that while 

 each of the salts was poisonous when used alone, when mixed in proper pro- 

 portions their toxic effects were countei'balanced. The results appear to be in 

 harmony with those of Loeb and others, who have experimented with animals, 

 and serve to emphasize the similarity between plants and animals in some of 

 their fundamental characters. 



Frost injuries to sycamore buds, H. von Schrenk (J/o. Bot. Ganl. Ann. 

 Rpt., IS (1907), pp. 81-83, pi. 1). — A description is given of frost injuries to 

 sycamore buds, which are said to have occurred over a considerable portion of 

 the T'nited States during the past season. The injury has been attributed in 

 some instances to other causes, but from the author's investigations it is ap- 

 parently due to severe frost occurring after the buds have begun to develop. 



Plant anatomy from the standpoint of the development and functions of 

 the tissues and handbook of micro-technic, W. C. Stevens {I'hUddelphia, 

 1907, pi>. \II+3.'i9, figs. ;.3G).— This book attempts to point out in a brief and 

 elementary way how plants have become adapted to the carrying on of their 

 functions through the evolution of the different tissue systems from a primitive, 

 undifferentiated tissue, and how the various tissue systems are adapted to the 

 carrying on of the plant's vegetative functions. 



At the close of each chapter there are given illustrative studies for the labora- 

 tory, designed to fix in the student's mind the principal features discussed. 

 These exercises are exi)ected to develop the more important features of micro- 

 technic and to give facility in preparing and examining the material. Chapters 

 are given in which are described in considerable detail methods for the prepara- 

 tion of sections, the use of the microscope, reagents and processes, and the 



