68 Tin; IM.AXT WOKLD. 



The anniversary falls on 'rinirsday. May 2-Tr(l, and will be 

 celebrated by exercises which will beiiin in the niurninii' at tlie 

 American Mnsenni of JvTatnral History with addresses and an 

 exhibition of the animals, minerals and rcx'ks known to science 

 in the time of Linn?ens; will continne in the afternoon at the 

 Botanical Garden and Zoological Park in Bronx Park with 

 addresses and suitable exhibits of plants and animals and the 

 dedication of the Linnieus Bridge, and will he conclndcd in the 

 evening with simnltaneons exercises at the Mnsenm of the 

 Brooklyn Institute and at the N^ew York Aqnarinm in Battery 

 Park. The scientific societies of the world will be invited to 

 partici]iate in the celebration. 



The very pronounced hardness and impenetrability to 

 water of many lec;umin<nis seeds is a well known fact. J3ergtheil 

 and Day (Ann. Bot. Jan. 1007) find this to be due to the occur- 

 rence of a thin outer layer of a cuticle-like substance which 

 upon treatment with sulphuric acid, swells and then allow^s the 

 entrance of water. The authors question the view of Jarzymow- 

 ski (Diss. Halle, 1005) who believes that the hardness is due 

 to the size of the lumina of the outer layer of cells of the seed 

 coat. A twenty-minute to half-hour treatment Avith sulphuric 

 acid, with proper after-washing, insures a ready germination 

 of otherwise refractory seeds. 



Studies of the embryology of the flowering plants carried 

 on from the standpoint of physiological interpretation are be- 

 coming more numerous. L. S. Gibbs (Ann. Bot. Jan. 1007) 

 has examined Slellaria and certain of its allies, with this princi- 

 ple in .mind. The earlier suggestion that the suspensor is useful 

 for food absorption is sujijwrted, and also that its function in 

 this regard is taken up by the endosperm in the later phases of 

 embryological development, as fomid to be the case in the Piper- 

 aceae by Johnson. 



Chamberlain (Bot. Gaz., February) announces the dis- 

 covery of motile spermatozoids in the pollen tubes of Dioon and 



