176 



OTTO VERNON DARBISHIRE. 



The tetraspores themselves are spherical in shape, and when 

 escaping at maturity they measure 10 — 12 jj. in diameter. They are 



wmmt 



mmmm 





Fig. 7. Acthiococcus roseus (Lyngb. ) Kold. Rosenv. 

 Vertical section of outer layers of nemathecium : a. sterile 

 outer cells of nemathecial filaments : b. tetrasporangia ; 

 c. sterile inner cells, and d. the cells of the parasitic 

 cushion, x 300 diam. 



