SOME PROBLEMS OF REPRODUCTION. 29 
the zygotes emits a tube which may abstrict spores or grow 
into a vegetative mycelium, This germination of the gametes 
may in some cases take place facultatively independently of 
conjugation.! 
Protomyces resembles Ustilaginee in the behaviour of its 
gametes; but they are formed endogenously in large numbers 
in the spore, leaving a quantity of non-nucleated epiplasm. 
In Urnepinex Massee has described a process of siphono- 
gamous* conjugation between a larger “oogonium” and a 
smaller antheridium comparable to that of the lower Asco- 
mycetes. The only cytological observations of importance 
given are that the oogonium is uninucleate before fertilisa- 
tion, and contains several small nuclei on the third day. 
C. Hicguer THALLOPHYTES. 
1. Floridez. 
The Red Seaweeds stand apart from the other Thallophytes 
in many respects, and we follow Falkenberg*® in regarding 
them as distinct from the true Alge. Their male reproduc- 
tive cells or “‘spermatia” are all but motionless, and scat- 
tered by local currents. Their female cells, “ carpogonia” or 
*‘ procarpia,’”’ are usually permanently fixed in the thallus. 
They emit a trichogyne which does not open, and is ab- 
stricted after receiving the male pronucleus by conjugation 
with the spermatium, and transmitting it to the female pro- 
nucleus in the base of the “ carpogonium.” 
1 It is noteworthy that the formation of gametes here takes place at a stage 
in no way homologous with the sexual organs of the (more primitive) Asco- 
mycetes. It would seem, indeed, probable that this gametal process has 
originated de novo as a specialisation of and advance upon the free anasto- 
moses formed between contiguous young hyphe in so many of the higher Fungi. 
There is, indeed, no reason why such processes should not originate afresh at 
a different stage in forms that have become apogamous by the complete loss 
of a sexual process at the usual stage. 
2 «On the Presence of Sexual Organs in ANcidium,” in ‘ Ann. of Bot.,’ 
vol. ii, 1888. 
3 In his monograph of the Alge in Schenk’s ‘ Handbuch der Botanik.’ 
