126 The Microscope. 



moulded in sparkling glass,, and every stem seems 

 twisted into a graceful spiral pattern. One almost 

 speculates as to the possibility of modelling the whole 

 thing on a large scale, with black velvet background, 

 as an ornament of rare elegance ; but where would be 

 the added charm of its living grace and varied move- 

 ments ? 



The account Dr. Carpenter gives of the branched 

 vorticellas is, that these infusoria, as well as many 

 others, multiply, plant-like by division. One sees an 

 usually wide head, and the same, after some hours, 

 may be observed to be actually double (see p. 112). 

 Then, in many cases, it breaks itself off, and reaches 

 the stage of existence, where it swims freely, and after 

 a while it fixes itself, and developes a new stalk. 

 Sometimes, however, instead of at once breaking off 

 when the double-headed stage is attained, the dividing 

 ' ' extends down the stalk, which thus becomes double 

 for a greater or less part of its length ; and thus a 

 whole bunch of vorticellae may spring (by a repetition 

 of the same process) from one base. In some mem- 

 bers of the same family, indeed, an arborescent struc- 

 ture is produced, just as in certain diatoms, by the 

 like processes of division and gemmation." Here Dr. 

 Carpenter refers to a figure, which is no other than 

 that of the diatom " Gomphonema geminaimn; 3 ' and, 

 on finding this, the reader may ask, "Why is that 

 diatom called a vegetable, and epistylis and vorticella 

 animals ? " There are certain considerations regard- 

 ing the different manner in which plants and animals 

 extract nourishment the former directly from the 



