Infusorial Circuit of Generations. 281 



moutli quivering with a sort of expressive smirk, and looking 

 altogether odd. 



They come full-sized and booming upon the stage, and in this 

 respect argue a direct derivation from certain haw-shaped, five- 

 costate vorticellan buds, with a contracted papims of stiffened cilia 

 around the orifice, spinning and rebounding like humming-tops. 

 The " goggle " now soon becomes stationary, and shortly after, 

 rapidly expanding, and its germinal speck or nucleus (the " eye ") 

 particularly enlarging, within half an hour it dropsically flattens 

 out into a pretty well-sized Oxytricha,* by a similar sort of internal 

 fluxile commotion of particles as when the animals dissolve into 

 molecular " sauce." 



But Oxytricha is not a perfect animal. It has no membranes, 

 and evidently no fibrous tissues at all. The entire texture appa- 

 rently remains in an embryonic, vitelline condition, as yet. 



I have in a single instance witnessed what appeared to be the 

 moulting of a perfect Oxytricha. The front border was somewhat 

 removed from the body, which it crowned like the crest of an 

 ancient helmet, and within each rigid bristle ("style"), as within 

 the fingers of a glove, was contained the far more delicate corre- 

 sponding one of a clear (and now entirely yolkless-bodied) animal, 

 the lower quarter being in a like manner hidden in a part of the 

 old coat. I thought it was plainly identical with the following 

 animal, whose development brings us up to '^ Paramecium Aurelia.'^ 

 As I have not been able to chance upon such a moulting process 

 again, I reserve the decision. 



A clear (internal) animal is apparently developed by this 

 moulting of the Oxytricha. Of the latter, the very bristles, when 

 detached, seem to possess individual vitality, singly beating about 

 for quite a while, and even empty coats (apparently sheet) some- 

 times behave as if they had a life of their own. At all events, at a 

 certain epoch there appears at once the next form in question, f in 

 full size upon the field ; the transparently clear bodies sometimes 

 showing a scalloped border, and alveoli, as o^ former yolks, extruded 

 — that soon smooth over. In outhne, the animal appears somewhat 

 like the soft parts of an oyster, being flat, somewhat lop-sided, in 

 the shape of a human ear — tip foremost. It is " doubled up " at 

 the straight border, the broader lower rim being overlapped, as hy 

 a lid, with a smaller, but thicker, upper flap (" lorica ") containing 

 one clear germinal speck. This animal o'pens like a hook, un- 

 doubling its flaps ; and it is thus that it devours its prey (such as 



* This somewhat resembles Gg. F, turning, by fluid expansion, into fig. E 

 (Carp. ' Micr.,' ibid.) ; fig. F, however, requiring to be duck-billed, as it were, 

 and fig. E to be lop-sided and the nucleus more central. 



t Perhaps the " Huplotes " of authors. Their descriptions and figures, however, 

 offer nothing that sufiicieutly resembles this very common form, so as to be readily 

 identifiable. 



