258 ON THE STRUCTURE OF OSCILLATORI.E. 



tions upon a single character, as though life were not a mani- 

 festation of a complicity of forces and conditions, becomes 

 every day more manifest. If, on the contrary, the motions 

 allowed to plants be limited to physical motions, depending 

 upon external causes, which is the favourite doctrine of the 

 present day, then we have no alternative left but to hand over 

 to the zoologist many organisms, and the Oscillatorioi amongst 

 them, which, in every other respect, are of undoubted vege- 

 table origin. Thus Mr. Hogg is in doubt whether the Diato- 

 macece are properly classed in the vegetable kingdom, because 

 thoy evince in their motions a controlling power independently 

 of a physical force, as intervals of rest and motion may be 

 clearly observed (Mic. Journ,, No. xi., p. 235), and Captain 

 Carmichael (Hooker, 1. c.) says, " I have bestowed consider- 

 able attention on such of the species of the Oscillatorice as fell 

 under my notice, and I do confess the result is something like 

 a conviction that they belong rather to the animal than to the 

 vegetable kingdom." This view of the nature of the Oscilla- 

 toricB might be supported by the fact that they evolve am- 

 monia when subjected to destructive distillation, and give off 

 carbonic acid gas in their living state as other animals. An 

 experiment made by me to that effect I twice repeated with 

 the same result, the particulars of which I will briefly state, 

 that it may be taken for quantum valeat. A quantity of the 

 frothy stratum of Oscillatoria was put in a bottle, nearly filled 

 with water, having its cork perforated by two glass tubes, one 

 a straight one, penetrating nearly to the bottom of the bottle, 

 the other a bent one, only perforating its cork, establishing a 

 communication with the air above the mass of Oscillatoria, 

 and another bottle, containing lime-water, on the principle of 

 a Wolfe's apparatus. After six hours, the lime-water gave 

 clear proofs of carbonic acid gas having passed through it. 



A third experiment made under the same conditions with a 

 mass of Confervse gave a negative result, and thus confirmed 

 the two former. Another circumstance worth mentioning is, 

 that the water in which they are kept is after some time ren- 

 dered slightly alcaline.* But to return to the previous ques- 

 tion: I would observe, that it might be shown, even if it be 

 granted that the inotions of the Diatomacece are spontaneous, 

 that they cannot on that account alone be regarded as animals, 

 because no solid reason has as yet been brought forward why 

 we should not admit even spontaneous motions in plants ; not 

 necessarily as proceeding from a consciousness or volition, but 

 as simple manifestations of instinct, blind impulses of their 

 vital force, yet withal indej)e7idcnt of and unconnected loith any 

 * At least in three instances this was the case. 



