Holtz : OBSERVATIONS ON PELVETIA. 37 



Paraphyses. When the disintegration of the cells to form 

 the conceptacular cavity is about finished, and while masses of 

 mucilage still encumber the cavity, the first appearance of the 

 paraphyses can be observed (PL V. , Fig. 2j; PI. XII. , Fig .38). 

 At this time the conceptacle is lined with one to three layers of 

 thin-walled, ovally flattened cells, which are devoid of chromat- 

 ophores or have only a few minute ones. The cells near the 

 ostiole have more color bodies. These cells are filled with a 

 granular protoplasm like the apical cell, though not so richly. 

 The walls of these cells do not stain as deeply as the other 

 cortical cells. The granularity referred to is evidently associ- 

 ated with activity in cell division. 



Paraphyses arise as protuberances on the inner wall of some 

 of the cells lining the conceptacle cavity. These protuberances 

 may in young conceptacles project halfway across the cavity 

 before they are cut off by a wall from their basal cells. The 

 paraphyses appear at first in the lower half of the conceptacle. 

 They very soon, even before they are cut off from their basal 

 cell, begin to turn toward the ostiole. 



As stated, the paraphyses in the main portion of the con- 

 ceptacle arise as lateral buds from the cells in the wall of the 

 conceptacle. The paraphyses at the upper end around the 

 ostiole appear to form somewhat differently. They look as if 

 they consisted of the unravelled or loosened cell rows of which 

 the conceptacle wall is composed, and which crop out in the 

 region near the top of the cavity (see Fig. 29). 



As the paraphyses develop their end cells especially divide, 

 though lower cells may do the same. The protoplasm remains 

 in communication between cells. The protoplasm is slightly 

 granular, nearly devoid of color bodies, except the end cells of 

 the paraphyses about the ostiole. These are well provided 

 with chromatophores, from which it would appear that their 

 function is in part assimilative. Mature paraphyses consist, in 

 the lower part of the conceptacle, of four or five cylindrical cells 

 of almost uniform diameter. The end cell is tapering. The 

 cells are about two or three times as long as wide. The para- 

 physes in the upper pa t of the conceptacle are more slender 

 and their cells are shorter and more numerous, eight to ten. 



The paraphyses are very numerous in a conceptacle. They 

 are especially numerous and crowded at the top, though they 

 are arranged here in regular, parallel order. In a few cases 



