On THE PlTHOPHORACE^i. 



53 



long, most frequently longer than the principal filament, and carry plenty of spores 

 (pi. 2,- fig. 1, 2). In tin 2:d the branches are considerably shorter than the prin- 

 cipal filament and carry each but a few spores (or sometimes but one) (pi. 2, fig. 3). 

 In the 3:d type the branches are still shorter, being generally formed of only a 

 subsporal cell and a terminal spore (pi. 2, fig. 4). The 4:th type is characterized 

 by a powerfully developed principal filament and an almost total want of branches ; 

 those few that are to be found are very small, almost rudimentary (pi 2, tig. 5). 

 The 5:th and 6:th type are represented by specimens which have only part of the 

 principal filament and part of the branches fertile, while the rest of the specimen 

 is sterile. Thus they are connecting forms between the purely fertile and the 

 purely sterile specimens. In the 5:th type particularly the upper part of the speci- 

 men is fertile, with short branches, and the lower part sterile, with long bran- 

 ches (pi. 2, fig. Gj. In the 6:th, on the contrary, the case is inverse, the lower 

 part being fertile with short branches, the upper sterile with long ones (pi 2, fig. 7). 

 The type oftenest met with is the l:st, and the least common is the 4:th. The 3:rd 

 is also rather uncommon. — In purely fertile specimens each supporting cell carries 

 but one branch. Once, but only once, 1 have seen two opposite branches carrying 

 spores sprung from one supporting cell. In specimens belonging to the 6:th type 

 af ramification two opposite branches are not seldom found on one supporting cell in 

 the sterile part of the specimen (in the same manner as in purely sterile specimens). 

 One of these two opposite branches is always much more slightly developed than 

 the other (pi. 2, fig. 7). — The branches are in this species always attached a small 

 space below the top of their supporting cells. This space is in general of the 

 same length as the diameter of the branch; but now and then it can be somewhat 

 longer or shorter. — Branchless cells in the principal filament are seldom found 

 (except in specimens belonging to the 4:th type of ramification). Accessorial branches, 

 sprung from the lower part of the cells, are rare. Sometimes the same cell deve- 

 lops both one normal branch near the top, and one accessorial near the base (pi. 

 4, fig. 7; pi. 2, fig. 9). — Helicoids are very rare. Among the great quantity of 

 specimens that I have examined" I have found helicoids but in three, and but one 

 in each. Two of these helicoids are represented in pi. 5, fig. 9 and 10. The first 

 ends a side branch, the second the principal filament. 



The spores occur both in the. principal filament and in the branches of the 

 l:st degree, and are brought forth both by the terminal and inclosed cells. The 

 inclosed spores are all of the same form, cask- shaped but more slender. Sometimes 

 they are so little swollen as to approach the cylindric form (pi. 2, fig. 3 sc). Now 

 and then they are provided on one side, near the top, with a process, greater or 

 smaller (pi. 2, fig. 3 sr), which is an indication of a branch, the formation of which 

 was commenced before the formation of the spore, but which was not continued. The 

 terminal spores are also cask-shaped, but not abrupt in their upper end, but with a 

 short point, somewhat rounded. Twin spores are very rare (pi. 3, fig. 8 s' s"). 

 Real triple spores I have not observed. The three spores placed besides each other 

 in pi. 3, fig. 8 are but seeming triple spores; and in the same manner the two spores 

 placed side to side represented in pi. 4, fig 3, are but seeming twin spores. Pro- 

 lific cells are sometimes found even in fertile specimens. 



