160 



INTRODUCTION TO CRYPTOGAMIC BOTANY. 



The branchlets form a close fastigiate mass, which unite above, 

 so as to make, by their confluence, a cellular envelope with 

 iiTegularly hexagonal cells. One or more new tufts are formed 

 at the apex, which again ramify, and thus the whole cactus- 

 like frond is generated (Fig. 42). In this state, however, the 

 plant is void of fructification, which does not, indeed, seem to 

 be produced very generally. The fructifying individuals pre- 



Fig. 42. 

 Halimeda opuntia, Lamx. 



Nat. size, and a portion of the threads magnified. From Mediter- 

 I'anean specimens communicated by Nageli. Specimens from Central 

 America, collected by Mr. Hinds, do not differ. 



sent little Confervoid tufts, divided repeatedly above, and 

 terminating in subglobose fastigiate branchlets. The endo- 

 chrome of these gradually becomes organised, and produces 

 innumerable active molecules, which, doubtless, are capable of 

 propagating the plant, as in allied genera, though their de- 

 velopment has not at present been observed. Cymopolia 

 appears to have fruit not very dissimilar from Halimeda, 

 as far as may be judged from Kiitzing's figures, taken 

 from dried specimens. The lateral threads which project 

 from the surface, bear an umbel of three or four branches, 

 each terminating in a swelling filled with granular matter, 

 while in their centre is a shorter branch, supporting a large 

 elliptic sac. Besides these threads, the terminal joints of the 



