422 



BOTANICAL GAZETTE [june 



spores 



be induced to germinate in darkness. Germination was best in light of medium 

 intensity (about 0.075 sunlight). Weaker light induced filamentous or ribbon- 

 like prothallia, while strong light induced heart-shaped prothallia. Strong light 

 (intensity 0.3) cause the production of only archegonia in Alsophila, while in the 

 other ferns both sex organs were produced. Weak light inhibits the production 

 of archegonia and favors the production of antheridia. — J. M. C. 



Poisonous action of salts.— Benecke^' mingles with a strong polemic against 

 LoEW an account of experiments which go to show that various salts collectively 

 harmless are individually poisonous to Spirog}Ta, but have their toxic action 

 neutralized by calcium salts. The chlorids, nitrates, sulfates, and phosphates 



potassium, magnesium 



The 



poisonous 



of the anions named the phosphate, sulfate, and nitrate are more poisonous than 

 chlorion. The toxicity of both anions and cations may be removed or dimin- 

 ished by the addition of Ca ions. 



These results are essentially those obtained by Osterhout and Duggae, 

 the chief difference being that Benecke ascribes to Ca a special antitoxic property 

 toward other salts. — C. R. B. 



Respiration and pollination. — When the gjnaecium begins its second phase 

 of development, after pollmation, the respiratory activity might be expected to 

 differ from that of an unpollinated one, but no comparative determinations seem 

 to have been made. This has now been done by Miss Jeak Whixe,'^ using the 

 Bonnier-Mangin apparatus for gas analysis. With due precautions she finds 

 this apparatus, as modified by Atjbert, entirely satisfactory. "The net result 

 of the whole work is to show that pollination not only produces a rapid rise of the 

 respiratory activity, but also affects the respiratory quotient," which is usually 

 less than unity and larger in the pollinated than in the unpollmated gynaecium. 

 The numerical data show such extraordinarj^ differences, under presumably Uke 

 conditions, as to raise serious question regarding the value of the observations. 

 C. R. B. 



r 



Embryology of Oxalis.— H.\:vniOND^3 has investigated O. carniculafa and 

 :ords that the single hypodermal archesporial cell does not give rise to any 



megaspore 



antipodals 



basal cells of the suspensor form a very active haustorium. — J. M 



LVKCKE, W., Ueber die Giftwirkung verschiedener Salze auf Spirogyra, unc 

 ;iftung durch Calciumsalze. Ber. Deutsch. Bot. Gesells. 25:322-337. i9^7 



EAK 



gynaecium. Annals 



AMMOND, Howard 



»4. pi- iS, 1908. 



Ohio Nat. 



