63 
theridial spots in P. leucosticta. They were found to consist of antheridia earlier in 
their development than the surrounding antheridia, which were still in division. 
As first shown by BERTHOLD (1880 and 1882), the spermatia attach themselves 
to the female portions of the frond, and a fine fertilization canal is formed through 
the wall of the carpogonium-cell. These fertilization canals contain a thin strand 
of protoplasm, which is still to be seen a long time after the fertilization, while 
the exhausted spermatium quickly disappears. Their number is often remarkably 
great, much greater than that of 
the carpogonia (fig. 5 A—C). It is 
evidently a very common case that 
several fertilization tubes are intro- 
duced to one carpogonium. 
The fertilised carpogonium 
divides, as is well known, by a 
transverse wall; thereafter follow 
olten one or two further transverse 
walls, whereupon arises a 3- or 4- 
celled prismatie body wich there- 
after may be further divided by 
differently orientated walls (fig. 5 
D, F). Such divisions result no 
doubt in cystocarps with numerous 
carpospores, while the typical case 
is regarded to be eight carpospores 
in two layers. Extraordinarily large 
cystocarps, containing a great num- 
ber of spores, were found in speci- 
mens collected in the harbour of 
Skagen dinvAprilishesrond ofiwhiehePrelgreswnlientn eyes Benson ne ERE Saen, 
was unusually thick, 90 to 1154 (fig. and, at a higher level, the fertilization tubes and in Aa spermatium 
ME TEE RS pean nie cies 
fig. 10. frond with cystocarps from the same locality, April. 230:1. F, in- 
completely divided cystocarp, Frederikshavn December. 500: 1. 
In anumber of specimens (52) 
collected in March on groins near Thyborøn, nearly all belonging to f. linearis. a 
few to f. laciniata, I found only cystocarps containing about 8 carpospores arranged 
in two layers, but in no case could spermatia or fertilization tubes be observed, 
and none of the plants contained antheridia. As the spores in all cases examined 
resulted from a division parallel to the frond, it may be supposed that we have 
here a case of apogamy, if it should not be found that the monospores can resull 
also from such divisions. 
The development of the cystocarps is as a rule uniformly progressive from 
the margin of the frond inward. Sometimes, however, the maturation takes place 
