260 ON THE STRUCTURE OF OSCILLATORIiE. 



takes place, has been decried by some as being unphilosophical, 

 without, however, their offering us a better interpretation 

 of those facts which gave rise to the proposition. In the same 

 manner seemingly well authenticated observations, tending to 

 establish a transition from a vegetable to an animal existence, 

 and vice versa, have been met by a similar dictum ex cathedra, 

 which is deserving of censure, though coming from a v. Sie- 

 bold or a Schleiden. Innumerable instances, from the insect 

 world alone, might be adduced involving metamorphosis not 

 less important as to the altered conditions of existence than 

 would be presupposed to take place in beings of the lowest 

 order, forming the boundaries of the two great classes, chang- 

 ing according to the varying external conditions from a vege- 

 table to an animal existence, and vice versa, and which might 

 have been set aside by a similar train of reasoning, were not 

 these phenomena from their nature capable of the most posi- 

 tive demonstration. 



Note. 



Since the foregoing was in print, further observations have 

 taught me, — 



1. That the appearances of the new species of Oscilla- 



toria, indicating a transition state, are produced by 

 the pressure of the thin glass cover when under 

 examination. And, 



2. That the alkalinity of the water in which some Oscil- 



latoria had been kept is traceable to the locality 

 from whence they came ; the water being of the 

 most filthy description, communicating with a sewer, 

 and largely impregnated with putrid animal matter. 



