IN THE MUD OF THE LEVANT. 13 



a different course ; now letting their rostra drop 

 and oscillating upon them, like balloons ere the 

 strings are cut, or like tops, their centripetal 

 force being nearly expended ; now altogether 

 stopping, and anon resuming their curious and 

 eccentric motions. Truly wonderful is the 

 velocity with which these microscopic objects 

 progress, their relative speed far surpassing that 

 of the swiftest race-horse ; after a time, however, 

 the motion becomes much retarded, and at length 

 the zoospores then lie as though dead. Not so, 

 however. They have merely lost the power of 

 locomotion. The vital principle is still active 

 within them, and they are seen to expand, to 

 become partitioned, and if the species be of an 

 attached kind, each zoospore will emit from its 

 transparent extremity, two or more radicles, 

 whereby it becomes finally and for ever fixed."* 

 The admission of indigo into the interior of the 

 Desmidea?, is a very unsatisfactory test, even had 

 it been observed to succeed in all cases, which 

 it has not. The increase by spontaneous division 

 is now shown to be exhibited by many of the true 

 Confervas, of whose vegetability there can be no 

 doubt. Indeed, it is probable that something very 



* Hassal's History of British Freshwater Confervae. Vol. i, 

 page 1 1 . 



