272 
Notes . 
male plants and carried to the female plants by air-currents, each 
antherozoid being surrounded by a thin film of water. 
Goebel 1 has suggested that the fertilization of the archegonia in the 
dioecious Marchantiales, which so often form isolated patches, might 
be effected by means of rain-drops falling upon the male receptacles 
and then splashing over the female plants. In the case of Mosses, 
in which similar conditions prevail, it was suggested by Kienitz- 
Gerloff 2 , and later confirmed by the observations of Gayet 3 , that 
small animals, especially insects, creeping over the patches of male 
and female plants may, especially in dry seasons, be instrumental in 
bringing antherozoids into contact with the archegonia. 
The examination of sections through antheridial receptacles of 
different ages shows that the development of the antheridia is accom- 
panied by that of air-spaces, which arise in the same manner as the 
chambers of the thallus, and whose sides are formed of cells con- 
taining abundant chloroplasts. Each antheridium becomes during its 
development sunk in a deep cavity, formed in essentially the same 
way as the air-spaces. As the antheridium grows in size, its cavity 
becomes flask-shaped, having a long neck opening above on the 
surface of the receptacle by a small pore which occupies the summit 
of one of the conical prominences already mentioned. Owing to 
the lateral pressure exerted by the growing antheridia, the air-spaces 
between the antheridial cavities become compressed and finally 
obliterated below, but in the upper portion of the receptacle they 
remain as wide chambers, each opening above by a pore of the 
* compound ' or ‘ barrel-shaped ’ type, the cells surrounding it being 
arranged in four or five superposed rings. The cells lining the 
chamber project inwards, and are often long, pointed, and colourless : 
exactly similar pointed cells are found in the air-chambers of the 
thallus, but they do not appear to have been previously described in 
the case of the male receptacle. As shown by the experiments of 
Kamerling 4 , it is from these colourless cells that water-vapour is 
given off into the air-chambers of the thallus, and very probably 
they have the same function here. In vertical sections the mature 
receptacle is seen to be divided into three well-marked zones :■ — (1) 
1 Organographie der Pflanzen, p. 310. 
2 Botanische Zeitung, 44. Jahrg. (1886), p. 250. 
3 Ann. des Sci. Nat., ser. 8, t. 3 (1897), p. 241. 
4 Zur Biologie u. Physiologie d. Marchantiaceen, Flora, 1897, p. 50 of reprint. 
