Development of Vaucheria Resting-spores. 169 
Now comes the question, what changes are undergone by 
the resting-spore in its ordinary condition, such as is shown 
in A, previous to its germination? It is very difficult to be 
certain as to this, but my impression, formed after the exami- 
nation of very large numbers of these bodies, is that in the 
normal course of development the corpuscles indicated in A 
almost completely disappear and that the general substance 
of the spore becomes resolved into a uniform mass of very 
minute granules. The spore has then a rather glistening 
silvery-white appearance, such as was seen in B. In the 
specimen represented in C there was much the same silvery- 
white appearance, but there were indications that a new set 
of rather smaller spheres was forming, leading on to the 
production of small glistening spheres of protoplasm such as 
are shown in D. Thereafter these small spheres seem to 
become green and converted into small chlorophyll-corpuscles. 
A specimen of this kind is shown in E, but in an early stage, 
as the corpuscles were still only of a very pale green colour. 
Pringsheim speaks of ‘‘ the innermost layer elongating,” and 
says it “breaks through the thick outer membrane, and 
becomes the young tube.” ‘These two layers are distinguish- 
able in H, which is, I believe, a spore becoming green and 
just about to germinate, while in fig. 8, D, the split in the 
outer membrane is recognizable. 
Pringsheim further intimates that these latter changes are 
rapidly brought about. He says, after a time the spore 
“suddenly resumes its green colour, and immediately there- 
upon grows into a young Vaucheria exactly resembling the 
parent plant.” As to the rapidity of these latter processes, 
my own observations do not enable me to make any definite 
statements, 
I now come to the most interesting and important point of 
all in connexion with the germination of the Vaucheria 
resting-spore, namely, as to the fate of the pigment-heaps 
which all along have been such prominent objects in the 
resting-spores. During my first examination of these germi- 
nating spores and on all subsequent occasions I have found 
either in the green spore itself or in one of the filaments 
issuing therefrom one or more of the blackish-green or red- 
brown pigment-heaps now appearing (when not pressed 
together or squeezed within a filament) as perfect spheres 
with sharply defined outlines, such as are shown in fig. 2 
(x 250). The most surprising thing at first was to see these 
pigment-spheres in the filaments, as in D and in H. -The 
latter body is ouly enlarged half as much as the others, in 
