the Marine Algcc of the Firth of Forth. 



431 



axis of the filament, and are not more than twice as long 

 as broad. In the lower part of the thallus there is a 



Table showing the maximum lengths and breadths of 

 emhxjoQ oi Enteromorpha comp'essa during the earlier 

 periods of growth. 



Date. 



Sept. 8. 



Max. Length 

 in mm. 



Sept. 12. 



Sept. 16. 

 Sept. 20. 

 Sept. 24. 



Sept. 28. 

 Nov. 1. 



0-0025-0 -0030 



Ma.x. Breadth 

 iu mm. 



•0025-0-0030 



0-145 



0-333 

 0-455 



0-600 



0-750 

 0-900-1-000 



0-0065 



0-0150 

 0-0200 

 0-0250 



0-0350 

 0-0450 



Kemavks 



Spores emitted. The figures 

 give the sizes of the 

 spores ill very weak acetic 

 acid Some of them ap- 

 pear quite spherical, 

 others are slightly ovoid. 

 A few are elliptical, most 

 are bluntly polyangular. 



Cell division in proximal 

 cells, Rhizoids differen- 

 tiated. 



Greatest diameter about 

 middle of embryos 



Rhizoids rapidy elongat- 

 ing. 



Greatest diameter slowly 

 passing backwards,o-win:c 

 to rapid elongation at the 

 apex. 



In some specimens division 

 has taken place in the 

 third cell from the apex. 



Bipartition occurs on the 

 average iu the sixth cell 

 from the apex. The cells 

 are here bluntly quad- 

 rangular, but become 

 elliptical towards the 

 base, and pass by further 

 elongation downwards 

 into the rhizoids. Rhi- 

 zoids average 0-12 to 0*15 

 mm. in length ( = one- 

 sixth approx. of the 

 entire embryo). Greatest 

 diameter of embryo dis- 

 tant about two - thirds 

 of its length from the 

 apex. 



slight contraction. The cells become somewhat elongated, 

 and pass by gradual transitions into the tiny rhizoidal 



