200 PROCEEDINGS OF THE AMERICAN ACADEMY 



velocity, even faster than the eye can follow in many cases. They 

 exhibit, by their activity, more plausible signs of animality than any of 

 the Desmidere or Diatomacea^, and fully as convincing indications of 

 life as the spores of Algte, to which they were first referred by the late 

 lamented Dr. "W. J. Burnet, and after him by Rudolph Wagner and 

 Leuckart. They have always been spoken of as developing around 

 decaying animal and vegetable matter. I was very much surprised to 

 discover the manner in which they originate from such substances. I 

 was studying the decomposing muscle of a Sagitta, a little crustacean, 

 as I consider it, — which, in passing, I would observe was found by 

 me a year ago last March, for the first time in this country, at Lynn 

 Harbor, — when I noticed large numbers of Vibrio 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 fibrillie 

 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, and others at times loosened themselves and swam 

 away. I was immediately impressed with the daring thought, that 

 these Vibrios were the fibrillfe 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 observations until I found some 

 fibres in which the fibrilliTe were in all stages of decomposition. At one 

 end of the fibre the ultimate cellules of the fibrillce were so closely 

 united, that only the longitudinal and transverse strise 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 ; 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, revolved 

 each upon its axis and swam away with amazing velocity. There was 

 no doubting, after this, the identity of the Vibrios and the muscular 

 fibrilhe ; but I thought such a strange phenomenon ought to have a 

 second witness to vouch for it, and therefore went for the best that 

 could be wished for, Professor Agassiz. I simply placed the prepara- 

 tions before him, and, without giving him the least hint of the origin of 

 the muscle, I was pleased to have him rediscover what I had seen but 



