316 Proceedings of the Royal Irish Academy. 



Association (Liverpool, 1896), some eminent authorities received the- 

 suggestion of " longitudinal fission" with an incredulity that bordered 

 on contempt. The object of this Paper is only to place the facts and 

 figures before them and others who may be interested, and ask for 

 an alternative explanation. 



I should add that I am much indebted to Mr. Hildage, late of the 

 Koyal College of Science, Dublin, for the time and care he devoted to 

 the production of the photographs reproduced in appended Plates. 



