256 BOTANICAL GAZETTE [octorer 
Griffithsia in the form and history of the holdfast. Though the 
spores of Callithamnion Borreri Ag. developed in the laboratory 
with difficulty, cultures sufficient to illustrate the order of devel- 
opment succeeded. After attaching themselves to the slide by 
an almost imperceptible secretion, the spores elongate and 
become pointed at both ends. The first division is parallel to 
the shorter axis (P/. XX//J, fig. 29), and by subsequent partitiona 
C. SALD. ae) / 
Fic. 1. Griffithsia Bornetiana Farlow, germinating tetraspore 
ing. X 333. 
Fic. 2. G. Bornetiana, plantlet 9 days old. X 213. 
Fic. 3. G. Bornetiana, holdfast of small plant grow 
Fics. 4, 5. Polysiphonia fastigiata Greville, growl 
Stack.; in fg. 5 the cells of P. fastigiata are shaded in, t 
merely outlined. & 213. 
g days after 9% 
ng on Ascophyllum gre 
hose of Ascophy as 
of the two f— 
Ju 
monosiphonous filament is formed. The smaller 
minal cells is the primary root-cell (77. XXII, fi: 32): chs 
from one set of cultures, the first cell of the hoi 
a very thick mucilaginous wall, is cut off from 
