Champia parvula , Harv, from the Carpospore . 347 
Development of the Growing-Point. 
Immediately after the segmentation of the spore, the growth 
of the young plant is more or less irregular. The cells at the 
base of the plant frequently divide very irregularly, and serve 
to strengthen the four organs of attachment. The space 
between the four small holdfasts becomes sooner or later 
filled in with cells, and a disc-shaped base is formed. One 
specimen was noticed in which the four holdfasts were present 
unaltered in a plant half a millimetre long. 
A plant, *15 mm. long, is figured in Fig. 9. The cells which 
probably agree in origin are numbered to correspond with 
Fig. 8. The apex of the young plant at this stage is very 
small, and is almost completely covered by the four cap- 
cells. At this time the growth of the young plants is very 
rapid. 
Because of the size of the young plants it soon became 
evident that it would be impossible to get satisfactory top 
and side views of the apex that would show how the groups of 
initial cells arise. Further study was carried on by means of 
microtome-sections. 
The plants had been well fixed in chromic acid, and very 
little difficulty was experienced in preparing them for sec- 
tioning. The young plants were very small, so for conveni- 
ence they were always left attached to a short piece of the old 
frond on which they had grown. They could be much more 
easily handled when thus attached to a short piece of the 
mother-plant. 
The specimens were all stained in alum-carmine ; the colour 
given them enabled the specimens to be oriented in the 
paraffin blocks more easily. They were treated with absolute 
alcohol in the usual way, and prepared for the paraffin by 
treatment with turpentine and solutions of paraffin in tur- 
pentine. In some cases the stain produced by alum-carmine 
was sufficient to show all the points, but usually it was 
necessary to stain again on the slide, and no stain was found 
so satisfactory for this purpose as Bismarck-brown. The 
B b 2 
