38 FIRST FORMS OF VEGETATION. 
mass of apparently living animalcules called sper- 
matozoids or antherozoids. These tiny organisms 
have short slender bodies, with long spirally-twisted 
tails, and display the most lively movements, each 
whirling upon its own axis, and quickly running 
about the field as if from an intense feeling of 
sensuous enjoyment. These movements generally 
cease in the course of two hours after the discharge 
of the spermatozoids from the antheridia ; but 
sometimes they are observed to move actively 
even after the lapse of two days. They are fur- 
nished with cilia like animalcules ; and their motion 
is such as would undoubtedly be attributed to 
ciliary action if seen in an animal structure. They 
are nothing more, however, than mere modifications 
of vegetable tissue ; and their motion is simply a 
hygrometrical action, like that of the teeth which 
fringe the mouth of the capsule. They are ex- 
tremely curious objects, and well worthy of the 
most careful examination. Inthe same receptacle 
among the upper leaves of the moss, may be.seen 
antheridia in every stage of development, those in 
the centre appearing to ripen first, even while some 
of those at the outer edge are of small size and 
quite green. There is thus a constant succession 
of spermatozoids produced; a provision which 
tends to insure their application to the pistillidia 
at the proper time. 
