Box— Vol. IL] HUS—PORPHVRA. 227 



the vegetative cells mixed with the sporocarps is due to the 

 absorption of the coloring matter by the reproductive cells; 

 but this hypothesis is not altogether satisfactory. 



The fronds are distromatic throughout, and any one 

 frond is fairly constant in thickness. But among the 

 various fronds a great difference in thickness may be 

 noted, some measuring but 100 microns while others 

 measure as much as 220 microns. But if the thickness 

 of each frond is constant throughout, the size and shape 

 of the cells in the various parts of the frond are exceed- 

 ingly variable. While at the base, the cells, especially 

 those possessing the hypha-like projections which form 

 the disc, are spherical or pear-shaped, the cells a short 

 distance away from the place of attachment are square, 

 measuring in each direction from thirty to fifty microns. 

 But the vegetative cells among the fully ripe sporocarps 

 are from thirty to sixty microns high and but from three 

 to ten microns broad. They appear to have assumed this 

 shape owing to much lateral pressure, being much elongated 

 and ofted dumb-bell shaped (PI. XXI, fig. 18). 



The great thickness of the surface jelly and the peculiar 

 markings of the walls of the vegetative cells are character- 

 istic of this species. The cell-wall appears to consist of 

 layers of jelly of different density. These seem to denote 

 stages in the cells existence ; but what these stages are 

 must at present be left to conjecture. 



This species appears to be dioecious, no antheridia having 

 been found. 



Sforocarfs. — The first division of the cell destined to 

 become a sporocarp is cruciate, which is followed by a 

 division parallel to the surface of the frond in each of the 

 subdivisions of the sporocarp, thus giving rise to eight spo- 

 rocarps arranged in two tiers of four each. Often another 

 cruciate division takes place, giving rise to thirty-two carpo- 

 spores (PL XXI, fig. 18). 



In Porfhyra variegata the jelly, especially that which 

 forms the partitions between the individual carpospores, 



