STUDY OF THE GENIÇTJLA OF CORALLIX.-K ]9 



When stained with Boemer's hematoxylin and fuchsin after the 

 method 1 mentioned in my former papers,^ we find at least three 



lamella 1 stained in différent degrees. The innermost lamella is pretty 

 thick, sharply distinguishable from the other parts of the wall (fig. 

 13). This part stains deepest in dark violet. If is the thickest of the 

 lamella? and is peculiar to the genicular portion proper. The genicula 

 •of the Corallinœ stain in a much deeper degree than the articular part. 

 This circumstance depends upon the property of this lamella. The 

 second lamella envelops the innermost lamella and varies in its 

 thickness, as it seems, according to the age of the pellicula. It stains 

 in pale violet or grayish blue. At the external part of the latter 

 lamella we have another thin lamella. This thin lamella practically 

 answers the middle lamella of the higher plants and is clearest at the 

 peripheral portion of the genicula ; and in some species it is entirely 

 invisible at the interior part of the genicula (fig. 14). In Cor. 

 yenoshimensis the three lamellae are very clearly defined (tig. 13). As 

 the cells are more or less polygonal and compressed by each other, 

 the outermost lamella is comparatively thick at the points where more 

 than two cells meet together, hi some spieces this lamella is to be 

 detected only at these points (fig. 14). In the genicular cells of 

 Amp. stelligera only the outermost lamella gives a deep violet colour, 

 while the other portions remain a light bluish colour. 



A peculiar modification of the wall was observed in the peripheral 

 portion of a geniculum which had been attacked by a parasitic alga. 

 The middle lamella stained exceedingly deep, while the second 

 lamella was quite indifferent to the colouring material (fig. 15). At 

 first the writer was induced to consider it the extra-genicular portion 

 cut lengthwise. l>ut the staining 1 mode is just contrary to the 

 ordinary case, and a further examination of the longitudinal section 



1) Cor. verje Ja^oa. P, 3 : Cor. verae of Port Renfrew P. 711. 



