PROCEEDINGS 



THE EOYAL IRISH ACADEMY. 



PAPERS READ BEFORE THE ACADEMY. 



I. 



ON THE PIPtST MITOSIS OF THE SPORE-MOTHEE-CELLS 

 OF LILIUM. By HENRY H. DIXON, Sc.D., Assistant to 

 the Professor of Botany, Dublin University. 



[Plates I. and II.] 



(communicated bt dk. e. p. weight.) 



[Read December 11, 1899.] 



"Within recent years so much, has been written on the nuclear divisions 

 taking place in the spore-mother-cells of the higher plants, and so 

 apparently divergent are the views, both as regards the general 

 process and the details of its history, that it might at first appear 

 from a survey of the literature that little had been definitely ascer- 

 tained. By a closer study of the recent memoirs on the subject such 

 an opinion will be dispelled. From these it will appear that there are 

 at least several stages in the process which are admitted, and which 

 have been constantly observed by the various investigators who have 

 made this subject their study, "Wide differences of opinion, doubtless, 

 exist ; but these are principally with regard to the processes by which 

 these well-established stages are derived from one another. Such 

 variance of opinion must be expected, seeing that the events cannot 

 be continuously observed from start to finish, and that such compli- 

 cated processes carried out on so minute a scale can often be only 

 indirectly inferred from an interrupted sequence of arrested stages. 



E.I. A. PEOC, SEK. in., VOL. VI. B 



