122 



SCIENCE. 



[N. S. Vol. XVI 11. No. -117 



upon the morijliology of the water molds 

 and their relatives. While it is impossible 

 to summarize this paper here, the present re- 

 viewer wishes to express his hearty agree- 

 ment with the conclusions reached by the 

 author. 



PEOTOPL.'^SMIO STREAMING IN PLANTS. 



De. Alfred J. Ewaet, of the Birmingham 

 Technical Institute, England, has recently 

 published an interesting book on the physics 

 and physiology of protoplasmic streaming in 

 plants which will attract the attention of 

 cytologists and no doubt help to give a better 

 idea of the mechanism of the streaming cell. 

 The work is the outcome of a series of obser- 

 vations begun nearly ten years ago by the 

 author and continued until quite recently. 

 It takes up first the physics and chemistry of 

 the subject, and this is followed by the phys- 

 iology, and then by a theoretical and general 

 discussion. A few results may be summarily 

 indicated as follows : 



The movement is generated in the proto- 

 plasm itself. 



The velocity of streaming is largely de- 

 pendent upon the viscosity of the proto- 

 plasm, and hence upon the percentage of 

 water, being more rapid as the water is in- 

 creased. 



Gravity exercises little or no influence upon 

 streaming in small cells, and only a very 

 slight one in large cells. 



High temperature affects streaming by de- 

 creasing the viscosity, and for each species of 

 plant or cell there are minimal, optimal and 

 maximal temperatures. 



No special chemical changes are connected 

 with the streaming of protoplasm. 



In the strongest magnetic field little or no 

 effect on the streaming is noticed, but elec- 

 trical currents may accelerate or, when strong, 

 stop the movement. 



Strong light retards streaming, while weak 

 light may accelerate it under certain circum- 

 stances. 



The book is one which must commend itself 

 to plant physiologists. 



FORESTRY IN NEBRASKA. 



■ Several years ago the Nebraska Park and 

 Forestry Association was organized for the 

 purpose of encouraging tree planting for 

 economic as well as ornamental purposes. 

 This organization has just issued a ' Park 

 and Forestry Manual ' which calls attention 

 to the kind of work which such an organiza- 

 tion may do for a community. This little 

 manual of nearly one hundred pages contains 

 many suggestive articles. There is first a 

 short article giving the origin of arbor day, 

 followed by one on the ' Forests and Forest 

 Trees of Nebraska.' Following this is 

 another on ' Tree Planting on Nebraska 

 Prairies,' and then in succession ' Propagation 

 of Forest Trees,' ' Raising Evergreens from 

 Seed,' ' The Nebraska Forest Reserves,' 

 ' Tree Planting in School Yards,' ' Trees and 

 Orchards,' ' Success or Failure in Timber 

 Claim Planting and Causes for It,' ' Home 

 Adornment and Public Parks,' ' The Red 

 Cedar for a Screen or Shelter ' and ' An- 

 notated List of Nebraska Trees.' This 

 manual might well be imitated by similar 

 organizations in other states. 



C. E. Bessey. 

 University of Nebraska. 



MODERN VIEWS OV MATTER.* 

 The Romanes lecture was delivered in the 

 Sheldonian Theater, Oxford, on June 12, by 

 Sir Oliver Lodge, F.R.S., principal of the 

 University of Birmingham, the subject being 

 ' Modern Views on Matter.' 



The lecturer began by saying that he would 

 discriminate between theses which were gen- 

 erally accepted by physicists and speculative 

 opinions or hypotheses which were now being 

 thrown out on the strength of experimental 

 evidence of an at present incompletely con- 

 clusive, but very suggestive, character. The 

 first thesis was that an electric charge pos- 

 sessed the fundamental property of matter, 

 called mass or inertia, and that if a charge 

 were sufiiciently concentrated it might repre- 

 sent any amount of matter desired. There 

 were reasons for supposing that electricit.y 



* From tlie London Tiiiirs. 



