Humphrey : OBSERVATIONS ON Gigartina exasperata HARV. 607 



Figure 8. Protoplasmic connections between cells of pseudo-medul- 

 lary area. x 900. 



Figure 9. An early stage in development of a proliferation showing 

 growing point (a). X 450. 



Figure 10. A portion of the margin of a frond showing prolifera- 

 tions and cystocarps. 



Figure 1 1. Longitudinal section of mature cystocarp. O, carpo- 

 stome; a, conceptacle. 



Figure 12. Portion of tissue surrounding a conceptacle showing cell 

 nuclei. X 7' 



Figure 13. Cross section of mature cystocarp showing spores. 



Figure 14. Two groups of spores separated by elongated sterile 

 cells. X 150. 



Figure 15. Immature carpospores still attached to the gonimo- 

 blastic filaments; () a spore separating from filaments. X48o. 



