Proceedings and List of Papers read. 



165 



or lower side of the much larger female nucleus. (See Guignard's 

 figs. 3, 4, 8, and 10.) In two cases the male nucleus is rounded, or 

 but slightly elongated. 



Eight embryo-sacs show the polar nuclei near the centre. In five 

 cases the mass is clearly made up of three nuclei, and the generative 

 nucleus is distinguished from the other two by its irregular shape, the 

 differentiation of a slender chromatic ribbon, and by the absence of a 

 nucleolus. In three embryo-sacs two resting nuclei are applied to 

 each other near the centre. 



The pollen tube is very clear in several preparations, and it com- 

 monly contains two small nuclei, stained green, and of irregular shape. 

 Since both generative nuclei are accounted for, these are probably due 

 to division of the vegetative nucleus. 



May 18, 1899. 



The LORD LISTER, F.R.C.S., D.C.L., President, in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The Bakerian Lecture, on " The Crystalline Structure of Metals," 

 was delivered by Professor Ewing, F.R.S., and Mr. W. Rosenhain. 



The following Papers were read : — 



I. " The Yellow Colouring Matters accompanying Chlorophyll, and 

 their Spectroscopic Relations." By C. A. Schunck. Com- 

 municated by Dr. Schunck, F.R.S. 



II. "The Diffusion of Ions into Gases." By J. S. Townsend. Com- 

 municated by Professor J. J. Thomson, F.R.S. 



III. " The Diurnal Range of Rain at the seven Observatories in connec- 

 tion with the Meteorological Office, 1871—1890." By Dr. 

 R. H. Scott, F.R.S. 



The Society adjourned over the Whitsuntide Recess to Thursday. 

 June 1. 



VOT. LXV. 



o 



