42] 



The Classification of Lower Organisms 



Fig. 5. — a, Porphyra laciniata, thallus x 1/2. b-g, Porphyra tenera after Ishikawa 

 (1921); b, cells; c, cell dividing to produce sperms; d, sperms; e, fertilization; 

 f, "carpospores," i.e., cells produced by division of the zygote; g, stages of nuclear 

 division x 2,000. h, i, Porphyra umbilicaris after Dangeard ( 1927); h, fertilization; 

 i, stages of nuclear division x 2,000. All figures x 1,000 except as noted. 



