DR. MARTIN BARRY ON FIBRE. 
109 
meets with ; difficult as they may be to account for, or even paradoxical as at times 
they may appear. 
86. It seems probable, however, that to the spiral structure of the filament (“ fibre”), 
we may attribute the elastic and resilient qualities of certain parts ; such as elastic 
tissue, and cellular tissue, as existing in and under the cutis, and in the parenchyma 
of the lungs ; the latter being intimately connected with the question, whether the 
lungs are resilient in expiration. 
8 7- Other parts in which the filament is found, as for instance some portions of the 
cutis, are capable of becoming constricted. The existence of filaments may be con- 
nected with that constriction. 
88. There is, however, one structure in which I have met with the filaments in 
question, that possesses neither elasticity nor resiliency, nor the property of undergo- 
ing either contraction or constriction, — bone. This objection I have not the means of 
answering : but may be permitted to remark, that although its original developement 
(the formation of its cartilaginous state) is after the same type, its completion, for a 
special purpose, is effected by the addition of bone earth. 
Analogy between the Tissues of Animals and Plants, after (as well as before) their 
Formation is complete. 
89. The remarkable uniformity in structure between the elements of animal and 
vegetable tissues, pointed out by Schwann, I showed in the Philosophical Transac- 
tions for 1840, to begin with the first foundation of the new being. It will now be 
seen, I think, from the foregoing observations, that a degree of this analogy between 
animals and plants exists, not merely in the elements of their tissues, but after the 
formation of the tissues is complete. 
90. That the nucleus of the vegetable cell, instead of being “ absorbed as useless,” 
after the formation of the cell-membrane, performs a part not less important than 
that which I have described as appertaining to it in animals, there can be no kind of 
doubt. I happen to have incidentally met with the germinal granules of the mush- 
room (fig. 27), and of the mould of cheese (fig. 26) ; and have figured them, as pre- 
senting evidence of this kind. Too much importance, it appears to me, has been 
attached, of late, to the membrane of the cell ; while the source of the contents of the 
cell, and apparently of all “ secondary deposits,” that is, the nucleus, has been 
overlooked. 
91. It is stated by Valentin that in plants, all “ secondary deposits” take place in 
spiral lines. I have already remarked, that in animals, spirals have heretofore ap- 
peared almost wanting. Should the facts recorded in this memoir, however, be esta- 
blished by the researches of other investigators, the question in future may perhaps 
be, where is the “secondary deposit” in animal structure, which is not connected 
with the spiral form ? But more than this : the spiral in animals, as we have seen, is 
in strictness not a “secondary” formation ; it is the most primary of all. And the 
question now, is whether it is not precisely so in plants. 
