64 THE ALGAE 



Primitive characters, which seem to be a feature of the genus, are 

 the numerous ova, the entire lack of specialized organs for repro- 

 duction and a simple form of zygote germination. The plant must 



Fig 

 Sph 



A » ^ 



34 Evolutionary development of life cycles in the genus 

 ■aeroplea. A=S. zvilmani type; B^S. camhrica type; C=S. 

 annulina type. (After Rieth.) 



probably be regarded as an Ulotrichaceous filament which, whilst 

 becoming non-septate, has still retained some primitive features. In 

 S. annulina cells are frequently found with only one or two plastids 

 thus showing a gradation towards Ulothrix. There would seem to be 

 very Httle justificationfor following those authors who would place the 

 faniily in the Siphonocladales (p. 8i), though it must be admitted 

 that S. africana does have some features characteristic of that order. 



REFERENCES 



General 



Fritsch, F. E. (1945). Structure and Reproduction of the Algae, Vol. I, 

 pp. 220-6. Camb. Univ. Press. 



Ulothrix 

 Gross, I. (193 1). Arch. Protistenk., 73, 206. 



Enteromorpha 



MuUer-StoU, W. R. (1952). Flora, 139 (1)5 148. 

 Sphaeroplea 



Rieth, A. (1952). Flora, 139 (1)3 28. 



Prasiola 



Fujiyama, T. (1955). Journ. Fac. Fish. Anim. Hush. Hiroshima Univ., 



J^ (1)3 15. 

 Friedmann, I. (i959)a. Ann. Bot. N.S., 23 (92), 571. 



Friedmann, I. (1959)5. Nova Hedwig. i, 3/4, 333. 



