EUPHYCOPHYTA 



95 



ranea have been used with systems ranging from 4 cren. nuclei: 

 o med. to cren. : 4 med. nuclei. The morphological features of the 

 discs exhibit a mixing effect but the form produced is not always 

 strictly proportional to the number of nuclei of the two different 

 species. 



Fig. 53 Acetahularia. A, plant of A. crenulata ( x o-8). B, apex of 

 A. mediterranea showing corona. C, apex of ^. tnoehii showing two 

 superposed fertile rhorls. D, A. mediterranea, attachment rhizoid 

 and perennating vesicle (6). E, A. crenulata, cells near centre of 

 thallus, showing superior corona (c) and leaf scars (5). F, A. pusiUa, 

 vegetative ray segment ( x 44). G, fertile lobes of A. schenkii with 

 cysts ( X 44). H, cysts in A. pusilla in a single lobe of the umbrella 

 ( X 37)- Ij single cyst of ^. mediterranea. J, young plant in first year. 

 K, L. A. crenulata, apieces of ray segments ( x 37). M, A. crenulata, 

 superior corona ( x 37). N, A. crenulata, inferior corona ( x 37). 

 (A, F-H, K-N, after Taylor; B-E, I, J, after Fritsch.) 



REFERENCES 



Acetahularia 



Werz, G. (1955). Planta, 46 (2), 113. 



Neomeris 



Daoa S. (1958). Revue Algol., 3 (4)3 192. 



