72 
HISTOLOGY Of VEGETABLES. 
In some of the lowest plants, as the Conferva, an act, 
called by botanists conjugation , takes place. Two 
filaments lie side by side, and very soon a nipple- 
shaped growth is protruded from opposite points of the 
filaments, these touch and eventually communicate ; 
one cell becomes empty, and in the other a spore is 
developed. The spore makes its escape from the parent 
57 cell, and swims about very actively 
by means of cilia attached to some 
part of its outer surface. In some 
species there is a pink spot in the 
centre of the spore, and such spores 
are no doubt not unfrequently de- 
scribed as Infusoria . The conju- 
gation of a Conferva is shown in 
Fig. 57 , and at a , a spore in pro- 
Conjugation of Con- 
ferva; a, spore in process cess of development. Spores pro- 
of development. 
vided with cilia are represented at 
cc and d , in Fig. 56. 
If we examine mosses of the genus Sphagnum and 
Polytrichum , in the spring, we find among the parts 
concerned in reproduction, certain elongated bodies 
termed Antheridia. If one of these be ruptured, a 
number of cells make their escape, and, if this be done 
in water, in a few moments we notice, with a power of 
two hundred and fifty diameters, the rapid movement of 
a spiral filament or phytozoon, in each cell. The filament 
has a globular head and a long tail, exactly like that of 
a Spermatozoon . When the phytozoa escape from the 
