THALLOGENS. 235 
of reproduction. It has been the subject of most interesting and 
minute investigations made by M. Thuret and Von Pringsheim. 
Its reproductive spores are, as we shall see, gifted at one period 
of their existence with a true movement, and it may actually be 
said to walk. This very remarkable fact shows how difficult it 
sometimes is to establish precise differences between plants and 
animals, and to define absolutely the limits of what are sometimes 
called the kingdoms of nature. ; 
The extremity of the filaments of this Fuci are swollen into a 
club-like form, and the green matter is condensed there until 
a 6 c d e 
25 
Fig. 304, Transformation ot Vaucheria. Fig. 305. Spore of 
Vaucheria escaping. 
it assumes a blackish tint. In Fig. 304 are represented the 
= Place. According to M. Thuret, the granules separate 
emselves slowly, the one from the other, towards the base of the 
like Swelling, leaving there a vacant space. The granules 
Proach each other again, and once more form a junction. 
then a great change takes place, for this singular operation 
how ap 
But 
