386 Dr. J. E. Dnerden on the Relationships 



the law first recognized by Ludwig, and also fully elaborated 

 by Kunth, and likewise clearly indicated by Pouital^s in the 

 septal scheme given on p. 50 of * Deep-sea Corals.' No new 

 septa arise within the two remaining primary interseptal 



Fig. 5. 



Transverse section from the same coral taken about the middle of its 

 length. Compared with tlie previous fiofure, an additional septum 

 (C) has appeared within the middle clianibcr on each side and also 

 ■within the lower chamber on each side (13), so that now three 

 «econdary septa occur within each pnniary middle system and two 

 within each primarj' lower system. Couifaring all the figures thus 

 far, the new septa of the former series are seen to always appear 

 immediately next the upper aspect of the lower literal primary 

 septum on each side, and in the latter series on each side of the lower 

 axial or counter septum. Each new septum is intercalated between 

 a primary septum and the la-^t-formod septum of the secondary 

 series, in each case on the same aspect of the primary septum. 



spaces. The sections further reveal that the small septa, 

 which in the mature coral alternate with all the larger or 

 principal septa, do not make their appearance until the growth 

 of the calice is nearly completed. From what is known of 



