49 



of the brandies, it is certainly not tlie case, as the deposit is 

 recent and the crust entire ; in the axillae of the branches it 

 is very common to lind several successive layers of the same 

 so regularly deposited as to preclude the idea of such a for- 

 tuitous enclosure. This opinion, therefore, of Ellis's, appears 

 to be erroneous, but is ratlier an error of deduction than of 

 observation. In the lower portions of the stem and in that 

 part near the roots, the cavities are frequently hollow or 

 without any of the white matter; some are only partially 

 empty, while in all the newer parts they are filled ; on this 

 point a very important question arises : Were these empty 

 and partially empty cavities ever occupied by the while 

 matter ? If not, they differ from the more recent and super- 

 ficial ones: If so, in what manner has it been removed? 

 questions which very materially affect the doctrine of the 

 inorganic nature of the axis. I consider these cavities to 

 have been filled like the more recent ones and that the mat- 

 ter afterwards became absorbed. From this it will be seen 

 that I am an advocate for the organic nature, and life of the 

 axis; an opinion that will be further supported hereafter. I 

 am quite aware that the opposite opinion is held by Dr. 

 Johnston, but witli all respect for such high authority I con- 

 fess that his facts and arguments are not of sufiicient weight to 

 make me alter my views; for the residual phenomena, for 

 which his theory fails to account, are so great and important 

 as to throw a very considerable doubt over it at least. Dr. 

 Johnston quotes Lamark as saying that the axis under all its 

 modifications is inorganic and formed by matter excreted 

 from the polypes, which afterwards become solidified by 

 affinity, this however is the result of theory rather than 

 observation and can therefore have no weight when opposed 

 to facts. 



The pith is central, white and runs through the trunk and 

 branches; and is smaller and more compressed in the older 

 than in the newer parts. Many persons, from the position 

 and dibtribution of the pith taken in coneclion with the con- 

 centric layers of the axis, have considered it a vegetable 

 stem. But there are several important discrepancies between 

 the pith of a Gorgotiia and an exogenous stem, which have 

 been noticed both by Ellis and Johnston. In vegetables the 

 pith is continuous from the trunk through all the branches 

 and is surrounded by a ring of vessels composed of tracheae 

 and ducts ; in the Gorgonia ii is not continued from the trunk 

 through the branches, but each oflFset is separated by several 

 layers of horny fibre and is in no way connected with the 

 pith of the trunk. It is also divided at short intervals, in the 

 Gorgonia, by transverse septa, and the brapches appear as if 



