CONTINUED: CLASSIFICATION. 



'73 



cluster called the sporocarp, which means spore-fruit or spore-fruit body. 

 In Batrachospermum it is seen as a compact tuft in the loose branching, in 

 Nemalion it lies in the surface of the cortex, while in Lemanea the sporo- 

 carps lie at different positions in the hollow tube of the sexual shoot. 



376. Gonidia in the red algae. The common type of gonidium in the red 

 alg:e is found in the tetraspores. A single mother cell divides into four cells 

 arranged usually in the form of tetrads within the tctrasporangium. In 

 Callithamnion the tetrasporangium is exposed. In Polysiphonia, Rhab- 



A 



Fig. 184. 



A red alga (Callithamnion), showing spor- 

 angium A, and the tetraspores discharged 

 B. (After Thuret.) 



Fig. 185. 



Gracilaria, portion of frond, 

 showing position of cystocarps. 



Fig. 1 86. 



Gracilaria, section of cysto- 

 carp showing spores. 



donia, Gracilaria, etc., it is imbedded in the cortex. In Batrachospermum 

 there are monosporangia, each monosporangium containing a single goni* 

 diui, while in Lemanea, and according to some also in Nemalion, gonidia 

 are wanting. 



