46 Excerpta Botanica. 



foremost, drawing after it the rest of the body, which turns 

 about in the water, but always preserves its turriculate form. 

 The incessant agitation of these tentacula and their extreme 

 tenuity rendered it impossible to observe them in the living 

 animal; recourse was therefoi'e had to the evaporation of the 

 water or to the appHcation of a slight tincture of iodine, when 

 the animalcules ceased their motions, became contracted, and 

 their spiral unrolled, when the tentacula were rendered very 

 distinct, from their brown colour. These tentacula were fre- 

 quently observed to be soldered together from one-half to one- 

 third of their length upwards, but others were also noticed to 

 be entirely separated down to their bases. A swelling similar 

 to that in the flexure of the body was perceived in their 

 curves. 



Ammonia arrested their motions and contracted the body 

 gradually into a small oval mass, but did not produce the 

 phfenomenon of decomposition by solution {diffliience) so re- 

 markable in the Infusoria. A very weak solution of chlor- 

 hydric acid in water violently contracted them into a shape- 

 less mass. 



In escaping from the filaments a portion only of the body 

 of the animalcule was sometimes disengaged, and fruitless ef- 

 forts were made by it to extricate the rest. In such cases it 

 was noticed that the portion bearing the tentacula invariably 

 remained within the tube of the filament. On the filaments 

 becoming empty, their divisions reappeared very distinctly. 

 No traces of the passage of the animalcule were observed, un- 

 less the brilhant points sometimes seen on each division of 

 the filament be regarded as such. 



The ovoid utricules accompanying the filaments are sphe- 

 roidal in the young anthers, but subsequently take the form of 

 an egg truncated at both ends, or nearly that of a parallelo- 

 gram, having one of its ends narrower than the other. Their 

 wall or paries is transparent, the orange granules contained 

 in them being of an elongated form, and lying in longitudinal 

 lines in the direction of the currents of circulation, their upper 

 extremity alone being destitute of them. 



In the interior of the utricules is frequently an oval globule, 

 generally motionless, but sometimes circulating with greater 

 or less rapidity along the walls. Besides this globule, which 

 is apparently formed of a granular fluid, are seen the rapid 

 currents ascending and descending longitudinally. These two 

 circulations, which are doubtless different appearances of the 

 same phaenomenon, occur either together or separately in the 

 same utricule. In some utricules the globule was motionless, 



