jANtTARY 29, 1915] 



SCIENCE 



181 



The behavior of seedlings of Lupinus albus 

 toward distilled water and toward simple solu- 

 tions of salts containing ions regarded as essen- 

 tial to the normal nutrition of higher green 

 plants was studied by the water culture method, 

 the plants being kept in darkness. The stronger 

 concentrations employed were comparable with 

 the soil solution under conditions found in the 

 vicinity of Washington, D. C. The absorption of 

 ions from the solutions and the loss of ions to the 

 solution were measured by the Wheatstone bridge 

 in terms of change of electrical conductivity. 



The plants give up their salts to distilled water 

 at a variable rate until death ensues from exhaus- 

 tion. Solutions of KH2PO4 and KCl act essen- 

 tially like distilled water. 



In K^SOi and KNO3 a slight absorption phase is 

 seen in the most favorable concentrations result- 

 ing in a minimal net gain in electrolytes to the 

 plant. Otherwise the results differ little from 

 those seen in the phosphate and chlorid solutions. 

 Sodiumi chloride affects permeability and growth 

 essentially like KNO3 and K^SO.. 



In the most favorable concentrations, of 

 Mg(]Sr03)2 and MgSOi there is a slight but clearly 

 developed absorption phase resulting in a net gain 

 of electrolytes to the plant. A net loss takes place 

 in the more dilute solutions and in the greater 

 concentrations toxic action develops. 



In CaCNOa), and CaS04 solutions all concentra- 

 tions studied support an active absorption of 

 electrolytes and apparently enable the plants not 

 only to retain the salts already present, but also to 

 make net gains from the solutions. 



The Absorption and Excretion of Electrolytes by 

 Lupinus albus in Dilute Solutions Containing 

 Mixtures of Nutrient Salts: E. H. Tetie and 

 Haklet Haeeis Baetlett. 

 Seedlings of Lupinus albus were grown in dark- 

 ness in graded solutions of pairs of nutrient salts, 

 the higher concentrations being comparable with 

 the soil solution. Absorption or excretion of elec- 

 trolytes by the roots was measured as changes of 

 electrical conductivity. 



The results obtained show that the gain or loss 

 of electrolytes by the plants is in eases influenced 

 by the antagonistic action of ions. 



The Transpiration Sate on Clear Days as Modi- 

 fied by the Daily Change in Environmental Fac- 

 tors: L-JMAN J. Beiggs and H. L. Shantz. 

 The transpiration of a number of crop plants 

 has been measured by means of automatic bal- 

 ances at Akron, Colorado, during the past three 



years. Automatic records have also been secured 

 of the evaporation from a freely exposed water 

 surface, the depression of the wet bulb, the inten- 

 sity of the solar radiation, the air temperature 

 and the wind velocity. The present paper com- 

 pares the results of such measurements for clear 

 days. The transpiration curves are based on a 

 large number of measurements, and expose the 

 normal behavior of these plants on clear days. 



delation of Transpiration to the Composition of 

 White Pine Seedlings: Geoege P. Buens. 

 The experiments reported at the Atlanta meet- 

 ing were repeated during the summer of 1914, with 

 the addition of two beds in which the physical 

 conditions were changed by means of one and two 

 covers of cheesecloth. The seedlings were grown 

 in five beds each with a different rate of transpira- 

 tion. 



Seeds 'Were sown in May and the first analysis 

 was made of seedlings gathered August 11. This 

 analysis showed the following amounts of protein 

 and soluble ash: 



This table again shows the high percentage of 

 ash in the full shade bed where the rate of trans- 

 piration was very low. 



A New Method in Lichen Taxonomy : Beuce Fink. 



The results of investigation of the CoUemaeesa 

 will be presented. The plants will be treated as 

 fungi and a new type of lichen diagnosis will be 

 presented. This will treat the anatomical charac- 

 ters of the lichen to the exclusion of those features 

 of the algal host which have heretofore been in- 

 cluded in the descriptions of these lichens. The 

 characters of the cortices and medullse have been 

 carefully investigated, and several features will 

 be presented which are new to lichen taxonomy. 

 The sex organs have for the first time been studied 

 with a view to ascertaining their value as diag- 

 nostic characters. Camera lucida drawings of 

 cortices, medullce, apothecia, procarps and sperma- 

 gonia will be shown, and their taxonomie value 

 will be discussed. 

 The Mechanism for Discharging the Eggs of 



Dictyota Dichotoma: W. D. Hott. 



The young eggs of Dictyota dichotoma are en- 

 closed by thin walls showing no differentiation, 



