Frccmav : oiiskhvatioxs ox coxstantixea. 185 



Holdfast. — The holdfast, i. c, the expanded portion of the 

 stipe at its base, presents a similar anatomical structure to that 

 of the stipe with the exception of one modification. The lower 

 cortical and intermediate areas which are in contact with the 

 surface to which the plant is moored are changed into a yellow- 

 ish brown disorganized mass which probably serves as a cement- 

 ing substance in attaching the plant to the rocks. Indications 

 of the former cell structure can be seen in occasional cavities 

 and in the arrangement of these cavities. The area adjoining 

 the cement layer is composed largely of elongated filaments 

 (Fig. 24). 



Protoplasmic Connections. — In freshly cut material the proto- 

 plasmic connections between cells, is very plainly to be seen in 

 many of the starch cells of the intermediate area. They are 

 also easily seen in the larger cells of the central area, as well as 

 in the small cells of the same area. The cortical area of the 

 stipe furnishes particularly good views of this continuity (Figs. 

 13, 18). 



Reproductive Tract (Y'xgs. 11, 12). — I have been unable to 

 find, in the material at hand, and it is considerable in amount, 

 any trace of cystocarp development. The following description 

 of the occurrence and structure of the cystocarp of the genus 

 is translated from Schmitz and Hauptfleisch,* the former of 

 whom has made a personal study of the cystocarp of C. rosa- 

 marina (Schmitz, 1. c.) : The carpogonial branches and aux- 

 iliary cell branches are distributed in the fertile portions of 

 the frond in large numbers in the loosened inner portion of the 

 inner cortex of the upper side of the leaf, together wuth numer- 

 ous vermiform sterile cellular threads. Cystocarps distributed 

 in large numbers on the fertile fronds, comprising a broad zone 

 along the edge of the frond on its upper surface, imbedded in 

 the much loosened inner cortex of the upper surface of the 

 frond, swelling out into an arch the superposed outer cortex 

 which is punctured by pores. The nucleus of the form of a 

 mulberry and pierced by single strands of sterile tissue. Goni- 

 molobes separated only at first, later confluent. 



Kiitzing t states that the " gongyli rotundi " described by 

 Postels and Ruprecht as two kinds of fruiting bodies in Constan- 

 tinea rosa-marina are ordinary cells of the cubcortical layer. 



* Schmitz and Hauptfleisch. In Engl, and Prantl. Nat. Pflanz. I. Teil. Abth. 

 2. 520, 521. 1897. 



t Phyc. Gen. 400. 1S43. 



