186 Mr. W. Gardiner. The Genesis and Development 



of copper sulphate and of sodium chloride, but found no electrification. 

 The present experiments lead to the conclusion that evaporation of 

 fused sodium does not give electrification, such as could be detected 

 by the method used, unless oxidation is going on. 



February 15, 1900. 



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 following Papers were read : — 



1. "The Genesis and Development of the Wall and Connecting 

 Threads in the Plant Cell. Preliminary Communication." By 

 Walter Gardiner, F.R.S. 



IL " Photography of Sound-waves and the Kinematographic Demon- 

 stration of the Evolutions of Reflected Wave-fronts." By 

 R. W. Wood. Communicated by C. V. Boys, F.R.S. 



" The Genesis and Development of the Wall and Connecting 

 Threads in the Plant Cell. Preliminary Communication." 

 By Walter Gardiner, M.A., F.R.S., Fellow and Bursar of 

 Clare College, Cambridge. Received February 1, — Read 

 February 15, 1900. 



In the course of my investigations in connection with the forth- 

 coming paper on " The Histology of the Cell Wall with special 

 Reference to the Mode of Connection of Cells," * certain observations 

 and conclusions concerning the origin and development of the wall- 

 threads and cell-wall have come to light which seem to be of suffi- 

 cient interest to warrant my bringing them to the notice of the Society 

 without delay. 



1. Origin and Development of the " Wall Connecting Threads." 



The " connecting threads " are found to arise from the median nodes^ 

 of the fibres of the achromatic spindle. The nodes are either {a) all 

 continued as connecting threads, e.g., the endosperm cells of Tamus- 



* * Roy. Soc. Proc.,' toI. 62, 1897. (Preliminary Corrimunication.) 



