22 



central joint, and consequently allowing more time for the changes to 

 take place. 



It would appear that the enveloping of the granules by an investing 

 membrane was a means of preserving the organic particles in a green 

 and probably therefore in a living state. But whether for the purpose 

 of regeneration under a different form (thus affording an example of 

 equivocal generation), or whether the phenomenon was in any way 

 connected with the reproduction of the plant, did not appear from any 

 observation that I could make, as no further change was observed to 

 take place in the brown bodies beyond that which has been described, 

 though they were kept in water for a considerable time. An appear- 

 ance similar to what appears to be the first stage of the process, is not 

 unfrequently observed in the living Cham, where a number of the 

 green granules collect together in a mass, which either passes along 

 with the general circulation, or remains revolving at one extremity of 

 the tube. But I am not aware that the brown bodies now described 

 have ever been seen in the living plant, nor have I met with any ob- 

 servations which at all illustrate the point. The phenomenon how- 

 ever appears to me to bear very closely upon the remarkable form of 

 tissue described as occurring in the Heme Bay fossil, and I have 

 therefore been induced to bring it before the Society, together with 

 the original drawings, which were made at the time of the observa- 

 tion, and the preparation of that portion of the plant from which they 

 were made, and which, though it has suffered from being kept for more 

 than five years, during which time it has become dry, will still, I be- 

 lieve, afford a fair idea of the structure alluded to. 



These brown globules, contained in the stems of Nitella, appear to 

 differ from the globules found in the vessels of the fossil wood chiefly 

 in the circumstance of their being hollow spheres in the fossil, but 

 capsules filled with green matter in the recent plant. 



