438 M. Eckhard on the Organization 



dreds in green globules not unlike frog's spawn. In the intes- 

 tine of the frog we find forms, some of which (especially Bursaria 

 ranarum) are inclosed in mucous envelopes, which reminds us of 

 similar occurrences among the Entozoa. 



Locomotive Organs. 



4. They are present in various forms, and furnish us with a 

 proof of the incorrectness of the view, that the lowest animal 

 beings throughout exhibit a more simple, homogeneous, and con- 

 sequently more imperfect organization than the higher ones. To 

 survey them, we shall consider them in the three following 

 groups : — 



1) Locomotive organs placed around the mouth. — The organs 

 which belong here, in whatever form they occur, are apparently 

 always organs of prehension, taste, &c, and hence, strictly speak- 

 ing, should be separated from the organs of motion. However, 

 as they correspond to the hands and other like formations of the 

 higher animals, they ought to be placed here. In the Rotatoria 

 they are much more perfectly developed in the so-called rotatory 

 organ, which appears in the most numerous and complicated 

 forms. The Polygastrica exhibit more simple forms, but still 

 sufficient difference to merit more accurate consideration. In 

 their simplest state they appear as one or two filiform proboscides, 

 frequently of such tenuity that they are only perceptible when 

 seen in motion between minute coloured particles. They exist in 

 greater number in Vorticella, Epistylis, Enchelys, &c. In these 

 instances they form a circle around the mouth, which consists of 

 either one or two rows of cilia, and then frequently exhibit sur- 

 prising resemblance to several kinds of rotatory organs. These 

 ciliary circles exhibit differences according to the different form 

 of the mouth. In many they are susceptible of retraction ; this 

 is most constantly the case in Epistylis grandis. 



2) Locomotive organs which cover the whole body, or may be 

 considered as lateral appendages. — In most of the Polygastrica 

 these are likewise cilia, the usual arrangement of which is in 

 longitudinal striae (probably muscular) corresponding to the axis 

 of the body, to which the former are attached. They often 

 appear in great numbers. In others the cilia are arranged in 

 circles which surround the middle of the body obliquely, as may 

 be seen very distinctly in the Peridincea. In Spirostomum ambi- 

 guum there is a row of cilia (6 A) running the whole length of 

 the body. In the Stylonychice they are remarkably different. 

 Their somewhat elongated oral fissure is surrounded by cilia of 

 the usual structure, those on the body being more rigid. But 

 what is most remarkable in them is, that they are not placed on 

 the muscular stria? which run longitudinally down the body, but 



