206 



will be seen that Ihe middlemost (primary) wall is inclined to the left, the two 

 others to the right ; the walls, however, do not intersect, in accordance with the un- 

 usually narrow shape of the sporangium. 



After the evacuation of the tetrasporcs, the sporangial walls are kept for a long 

 time ; they swell and fill the conceptacle. They have been considered as paraphyses 

 by KuTZiNG and others, but such organs do not occur in the adult conceptacles 

 (comp. ScHMiTZ and Hauptfleisch 1. c). Small Sarcina-l'ike bacteria sometimes 

 form strings between the empty sporangial walls. 



Conceptacles are met with at all seasons, and ripe sporangia have been found 

 in all the months of the year, most fre({uently, however, in summer. As a rule 

 empty, ripe and unripe sporangia are found simultaneously, from which it must be 

 concluded that the formation of sporangia continues during the whole year, in the 

 winter onl}' with diminished activity. At what moment the development of the 

 conceptacles begins I cannot say with certainly as I have seen but a small number 

 of young stages. The youngest of the observed stages (fig. 123 A, B) were met with 

 in June, which might suggest that the development of the conceptacles begins in 

 spring, when the growth of the crust must be supposed lo be active. 



In older crusts the periodicity of the growth is marked by distinct limiting 

 lines between the layers of the successive years. The upper line in fig. 121 probably 

 represents the surface of the frond at the end of the foregoing season, but the lower, 

 more irregular line does not represent an old surface; the deepenings are the bot- 

 toms of emptied conceptacles, and the higher |)arts between them represent tlie 

 limit of Ihe crust after disorganisation of its upper parts. It really frequently hap- 

 pens that the outer cell-layers die in winter over a greater or lesser part of the 

 crusl, and the faculty of growth is then often restricted to limited portions of the 

 frond, which then become higher, and provided with conceptacles, while the other 

 parts are low and sterile. 



The species is widely spread in the Danish waters, particularly in shallow 

 water, also over the low-water mark, and in sheltered places, where it is often a 

 characteristic element of the vegetation, covering the stones with a red crust in 

 company with Halfsia etc., frequently under Fiicus. But it is also common in deeper 

 water, even in the greatest depths where vegetation has been met with, e. g. in 

 the North Sea at 31 meters depth, in the Little Belt at 26,4 m and near Bornholm at 

 38 m, but it seems to be less abundant at greater depths. It has repeatedly been 

 met with in a fructiferous state at about 19 meters depth, at Bornholm even at 

 29 m. In very insolated localities in shallow water it takes a yellowish colour during 

 summer. 



Localities. Ns : aF, off Tlij'boron, 31 meters, small sterile specimens; groin at Thyboren. — 

 Sk: YU, Kosliage, Hanstholm, 2 m, small sterile spec; washed ashore near Bulbjerg, sterile; Hirshals, 

 on stones adhering to the hapters of Laminari;e washed ashore after storm, sterile. — Lf : Rennen near 

 Lemvig, 3 m, MA, off Jestrup, .5 m; Oddcsund, stone slope, fr. ; Nykebing and otherwhere in Sallingsund; 

 aT', Draaby Vig; Live Bredning (C. H. Ostenfeld;; west side of Feggeklit. — Ku: Herthas Flak, 21 — 25 m, 

 ster.; Hirsholmene; Deget; Busserev; Frederikshavn ; Nordre Renner. — Kui; Mariager Fjord, at Hobro; 



