146 



SEAWEEDS 



joined to Acetdbularia, and these are characterised 

 by the radiating chambers being free from each 

 other, and by other differences. 



The best studied species is A. mcditerranea, and a 



FIG. 43. a, Acetnbularia exigua decalcified (magnified) ; b, Acicularia MiJbii, 

 longitudinal section with two superposed caps ; c, Acetabularia Calyculus, 

 cap-ray with spores showing upper and lower coronse ; d, A. exigua, spores 

 with lid. b, c, d highly magnified. (After Sohns-Laubach.) 



description of it will enable us to understand the 

 variations displayed by the others. It has an erect 

 stalk six to nine centimeters high, with a cap about 

 a centimeter across, strongly calcined and parti- 

 tioned into a number of regular radial chambers, 



