315 
short (7—9 « thick, 160—290 w long). The pit connecting the hair with the bearing 
cell is very distinct. The hair-bearing cell cannot function as apical cell but it 
may produce a branch which sometimes grows out approximately in the same 
Fig. 225. Fig. 226. 
Callithamnion Brodiei. Parts of tetrasporiferous plant. 158: 1. Callithamnion Brodiæi. Parts of male plant. A 77:1. B220:1. 
direction as the mother axis, the hair being pushed aside (fig. 225 C). In the ob- 
served cases the hair was pushed towards the dorsal side of the filament. The pro- 
cess may be repeated in the same filament. 
The tetrasporangia are placed on the branches of higher order, principally on 
the upper side of the branchlets, on the first joint, on two or three consecutive ones 
or more irregularly. There are frequently two on the same joint and then the younger 
below the older or obliquely beside and below it (fig. 225). The undermost sporan- 
gium may be placed on the middle of the joint which may also be the case with a 
single sporangium (225C). A seriate arrangement as regular as in Harvey's figs. 3 
