BIHANG TILL K. SV. VET.-AKAD. HANDL. BAND. De N:O De 7 
If we observe the sporocarpium of the Mesocarpee espe- 
cially as to its construction, we find that it is always mono- 
sporous, but that the number and place of the cells forming 
the pericarpium may vary: The researches of pE BArRY quot- 
ed above have shown that the sporocarpium is formed 
(or according to the view of DE BARrRY, that the zygospore is 
divided) either by tripartition or quinquepartition, the former 
being the case in the groups of Craterospermum and Meso- 
carpus, the latter in the group of Staurospermum. In the for- 
mer case the spore is rounded or cylindric; and the cells of 
the pericarpium 2, placed one on each side of the spore”?). 
In the latter case the spore is quadrangular and compressed; 
and the cells of the pericarpium are placed one at each of 
the four angles of the spore. — The knowledge of the different 
forms in which the sporocarpium of the Mesocarpew may appear, 
has later been enlarged by P. T. CLEVE by observations 
upon a plant which this author makes a type of a distinct 
genus, Plagiospermum”). The sporocarpium of this genus 
consists, besides of the spore, of 3 cells forming a pericar- 
pium and arranged almost as our fig. 16 shows”). At the con- 
nubium the chlorophyllcoloured protoplasm has here accu- 
mulated in the conjugation-canal and in the middle part of 
one of the conjugating cells, instead of accumulating, as in 
Mesocarpus and Craterospermum, solely in the connecting canal, 
or, as in Staurospermum, filling both the connecting canal 
and the middle part of the two conjugating cells. The for- 
mation af three septa is required to confine the space occu- 
pied by the chlorophyllcoloured protoplasm, and consequently 
a pericarpium of three cells is formed besides the carpospore. 
It is known, that in Mesocarpew in general no difference as 
to sex exists between the cells which participate in the 
fecundation. They are not only perfectly of the same nature 
before the fecundation, but act also during the copulation 
and connubium in a perfectly similar manner. But here, in 
1) When longitudinal conjugation takes place, as is common in Mougeotia 
genuflexa (Dillw.) Ag., the two cells of the pericarpium are made to lie 
on the same side of the spore. Compare our fig. 19. 
?) See P. T. CLEVE, Försök till en monografi öfver de svenska arterna af 
algfamiljen Zygnemacere, in Nova Acta Reg. Soc. Scient. Upsal. Ser. III, 
NOERKVISIIr868. i 
3) This fig. does not, however, represent the genus Plagiospermum. See 
on this just below. 
