322 Transactions. — Botanyt. 



a later stage, pyriform; and when nearly ripe, obovoid. (PI. XIII., figs. 4 

 and 8.) 



I have had no opportunity of studying the fertilization of this seaweed, 

 but am assured by Prof. Hutton that April is the best time of the year to 

 witness it, and that it is over by June, being evidently confined to the 

 autumn months. I have only to add that my thanks are due to the above- 

 named gentleman, for the kind interest he has manifested in the subject 

 throughout. 



DESCEIPTION OF PLATES XIII. and XIV. 



(All the figures natural size unless otherwise specified.) 

 Hormosira hillardieri. 



Plate XIII. 



1. Epidermal tissue of polygonal cells (x about 180 diam.). 



2. Longitudinal half-section of node, showing limiting, cortical, and parallel 



tissues (x about 120). 



3. Transverse ditto (x about 120). 



4. Longitudinal section of tissues of internode, showing limiting, cortical, 



irregular, and parallel tissues ; also female conceptacle with multi- 

 cellular hairs, paranemata, and oogonia (X about 60). 



5. Transverse section of tissues of internode (x about 60). 



6. Longitudinal half-section of node and ends of two internodes, showing 



stoppage of most of parallel cells at distal end a, and their division 

 into two parts at proximal end 6 (x about 40). 



7. Multicellular hairs of conceptacle, J length, showing division into cells 



(X about 180). 



8. Paranemata and oogonia, latter nearly mature (x about 180). 



a. oogonium with contents divided into four parts, one of 



these partly hidden by remaining three. 

 6. oogonium with contents differently divided. 



9. Branch bearing antheridia (x about 180). 



a. Empty antheridial cells (outer cell -wall of antheridium) . 



b. Escaped antheridium (inner cell- wall enclosing anthe- 



rozoids). 



c. antheridium, not fully mature. 



Plate XIV. • 

 la. Portion of frond, showing trichotomous branching from upper internode. 



Side view. 

 1&. The same branching internode. Top view. 



2. End of branch showing qnadrichotomous branching, and young internode 



springing from side of an older one. 



3. Lateral branching from internode. 



4. Union of two internodes near their base. 



5. Ditto. 



