295 
of Edinburgh, Session 1867-68. 
species of Vaucheria and in Fungi, such as Bhizopus nigricans. In 
the last-mentioned plant the compound spore is called a Zygospore. 
Special attention was drawn to the fertilisation of Florideae, as 
demonstrated by Bornet and Thuret. The formation of antheridia 
with corpuscles, and of a peculiar hair-like body called Trichogy- 
nium was noticed. The cell at the base of this latter organ, after 
fertilisation, is transformed into the Gystocarp, which is some- 
times supported on cells called the Trichophore. The formation 
of the Cystocarp containing spores was exhibited in large drawings 
of Nemalion, Batrachospermurn, Helminthoro, Liagora, Callitham- 
nion, Bonnemaisonia, and Polysiphonia. It was shown that, in the 
case of Dudresnaya, there is a long Trichogynium with spiral coils 
near its base, and that the cells below that organ elongate so as to 
form flexuose filaments, which pass in a serpentine manner among 
the ramifications of the sea-weed, and come in contact with the 
fructiferous filaments which they are destined to fecundate. These 
conducting tubes are attached successively to the terminal cells 
of the filaments, becoming incorporated with them. Thus, the 
fructiferous filaments are united together by a sort of network of 
delicate tubes. These tubes convey the fertilising influence from 
the Trichogynium to the Ampullae, from which the Cystocarps are 
formed. It was thus shown that the fecundating apparatus of the 
Florideae consists of antheridia containing corpuscles, and of a 
small cellular body terminated by a unilocular hair or Trichogynium. 
Fecundation is produced by the union of antheridian corpuscles 
with the Trichogynium, followed by the development of the capsular 
fruit or Cystocarp. 
In some cases, as in Nemalion, the fertilisation is direct, the 
influence of the antheridian corpuscle being at once conveyed by 
the Trichogynium to the rudimentary cell of the Cystocarp. In other 
cases, as in Dudresnaya, the action is less direct, — the influence of 
the antheridian corpuscles being conveyed by connecting tubes, 
which pass laterally from the base of tl^e Trichogynium to numerous 
fructiferous filaments, on which the Cystocarps are finally de- 
veloped. 
The author then considered the case of the spores contained in 
the Thecae of Mosses and Ferns. These spores have not been shown 
to be produced by direct fertilisation. In these plants there is a pro- 
VOL. VI. 2 Q 
