96 THE PERSISTENCY OF VITALITY 



decaying animal and vegetable matter. I was very much sur- 

 prised to discover the manner in which they orig- 

 inate from such substances. I was studying the 

 decomposing muscle of a Sagitta when I noticed 

 large numbers of Vibrio (fig. 49, e, c,) darting hither 

 and thither, but most frequently swarming about 

 the muscular fibres. I was struck with the similarity of these 

 bead-like strings to the fibrillae of the muscle, and upon close 

 comparison I found that the former were exactly of the same 

 size, and had the same optical properties as the latter. Some 

 of these appeared to be attached to the ends of the flat, ribbon- 

 like fibres (i), and others at times loosened themselves and swam 

 away. I was immediately impressed with the daring thought, 

 that these Vibrios were the fibrillse set loose from the fibres ; but 

 as this was a thing unheard of, and so startling, I for the time 

 persuaded myself that they must have been accidentally attached 

 and subsequently loosened. However, I continued my observa- 

 tion until I found some fibres in which the fibrillse were in all 

 stages of decomposition. At one end of the fibre the ultimate 

 cellules of the fibrilla? were so closely united, that only the 

 longitudinal and transverse striae were visible ; further along, the 

 cellules were singly visible, and still further they had assumed a 

 globular shape ; next, the transverse rows were loosened from 

 each other excepting at one end (a) ; and finally, those at the 

 extreme of the fibre were agitated, and waved to and fro as if to 

 get loose, which they did from time to time, and, assuming a 

 curved form, (e, c,) each revolved upon its axis and swam away 

 with amazing velocity. 



" The number of ultimate cellules in a moving string varied 

 from two to fifty; the greatest number of strings were composed 

 of only three or four, often six to eight, and rarely as high as 

 fifty. Very rarely the fibres split longitudinally, and in such 

 instances the fibrillse were most frequently long, and moved 



Fig. 49. A piece of the flat, ribbon-like, muscular fibre of a Sagitta. 1000 

 diam. t, the fibre ; a, fibrillse separating from the fibre ; e, c, fibriUae separated 

 and moving about like Vibrios. Original. 



