MAKINE ALGM, WITH A NOTE ON THE FRUCTIFICATION OP HALIMEDA. 167 



MM. Derbes and Solier ("Mem. Physiol, d. Algues," ' Compt. Rend.,' Suppl., vol. L, 

 185G, Plate XII., fig. 3) have figured a condition of the fruits of H. tuna, showing 

 the sporangiophores and sporangia filled, all hut the actual apex, with a dense, dark 



Halimeda gracilis. 



Fig. 1. Joints with fructification. Nat. size. 

 Fig. 2. One joint with fructification, x i. 



Fig. 3. Sporangiophores bearing sporangia in a condition shortly preceding the ejection of the zoospores. 

 The point of fusion of the two filaments of the central strand is shown at the base, x 41. 



green protoplasm. In the condition figured in this note, the development has advanced 

 a stage further, and the dense protoplasm has hecome almost entirely concentrated in 

 the sporangia and the apex of the sporangiophore. 



Of the subsequent escape of the zoospores I can say nothing. 



