On the Pithophoracb^e. 



31 



3 ]), p"). The germination of the prolific cells then takes place in exactly 

 the same manner as the formation of normal branches from common 

 cauloid cells. The new specimen will thus appear as a normal branch, 

 placed just below the top of the prolific cell. The increase of the new 

 specimen follows exactly the same lav\js that are valid in the increase 

 of the cauloid in specimens which originate in spores. In consequence 

 of this, unbranched specimens are very seldom found (pi. 2, fig. 3, the 

 specimen developed from the prolific cell marked p'). As a rule, the 

 specimens originated in prolific cells are like the others, more or less 

 powerfully ramified (pi. 2, fig. 2, and fig. 3, the specimen developed 

 from the prolific cell marked pi). Of course no rhizoid exists in the 

 specimens formed by prolific cells. In the germination of an isolated 

 cell, or of one which is terminal in a series of cells, it sometimes hap- 

 pens, that the prolific cell, besides forming, laterally, a new specimen 

 in the manner described above, also develops a cell in its upper end 

 by apical increase, succeeded by bipartition. In this manner the upper 

 one, .j/, of the two prolific, cells which are represented fig. 3 on pi. 2, 

 has proceeded; and the vegetative cell formed in this manner has, in 

 this case, even had the power to form in its top a spore, st. All the 

 specimens originated by prolific cells which I have seen, have been 

 fertile. Of course this does not prevent sterile specimens from being 

 perhaps also sometimes formed by prolific cells. 



Appendix. On the power of the protoplasm to heal 

 wounds which have been inflicted upon it. 



Although it does not strictly belong to the subject, I may be 

 permitted to mention in two or three words a phenomenon which I 

 have had the opportunity to observe in P. kewensis nob. PL 2, fig. 10 

 shows a piece of a sterile specimen attacked by a great multitude of 

 small protozoa. They have pierced the cell membrane and entered the 

 cells, intending to revel upon the protoplasmatic contents. In the largest 

 of the represented cells they have entered the middle part of the cell 

 and consumed a great part of the protoplasm there, before having en- 

 cysted themselves. Part of the protoplasm has, however, been left in 

 both ends of the cell. In spite of the damage which has been inflicted 

 upon the protoplasmatic tube belonging to one individual cell, the remaining 

 parts of it have not died. These parts, which form, in consequence of 

 the destruction of the middle part of the protoplasmatic tube, short 

 sacks open at the ends which point towards the middle part of the cell, 

 have had the power to close these openings, and to form from the new 



