134 



THE DISTINCTION BETWEEN 



Fig. 70. 



Fig. 72. 



Unless I were to point out their differences, you could not dis- 

 tinguish the true Infusorians from the false ones. Which they 

 are, respectively, I will explain presently. 



Thuret discovered that the seeds (spores) of certain marine 

 (Algae) and fresh-water (Confervas) plants have attached to 

 them peculiar threads, or cilia, with which they move ; and he 

 also pointed out their resemblance to the published figures of 

 certain so-called Infusorial animals. 



To prove what is the real character and relations of these cil- 

 iated spores, he spent a number of years in the investigation of 

 the mode of reproduction of a large number of different kinds 

 of water-plants, such as are commonly called sea-weeds and 

 pond-weeds. The process which Thuret adopted, in order to 

 carry out his proofs to perfection, although laborious, was the 

 only one that could be successful. At first he watched the grad- 



Fig. 70. Heteromita fusiformis, n. sp. 500 diam. e, the contractile vesi- 

 cle ; /, the anterior probocis-like vibrating lash ; Z 1 , the trailing lash. Original. 



Fig. 71. Heteromastix proteiformis. Nov. gen. et sp. 500 diam. A, an in- 

 dividual fully extended ; e, the red eye-spot ; ?, the anterior lash ; Z 1 , the pos- 

 teriorly trailing lash ; c/, the group of vibrating cilia. B, a contracted individual ; 

 2 , same as I ; c/ 1 , same as cl. Original. 



Fig. 72. Euglena spirogyra. Ehr. 300 diam. e, the eye-spot ; I, the vi- 

 brating lash. Original. 



