156 Miscellaneous. 
brown colour, as well as those seven the pore-grains of which assume 
a blue tint,—which grains iodine proves to be real starch. It would 
be remarkable indeed, if the substance in the former were not also 
of a similar nature to starch,—if it were not in fact isomeric with 
starch. 
Qndly. It would also be most remarkable, if plants of the same 
family, the nectaries of which agree with one another in situation 
and structure, should in some cases contain starch in the nectary 
and in others a different substance. Amongst the Labiate, for in- 
stance, it is indisputable that the nectaries of Mentha arvensis and 
Clinopodium vulgare contain starch. It would be extraordinary in- 
deed if the contents of the nectaries of many other Labiate, as of 
Stachys sylvatica and arvensis, Prunella vulgaris, Lamium album, &c., 
were not also starch, although they are turned brown by iodine, for 
their nectaries are in all other respects exactly similar to those of the 
first. 
3rdly. The elements of starch (C!*, H'°, O10*) form also with the 
same number of atoms three or four other substances, dissimilar in 
their chemical and physical properties, viz. cellulose, inuline, dex- 
trine, and lichen starch. Schleiden, however, in his ‘ Wissenschaft- 
liche Botanik,’ 1846, does not consider lichen starch as a distinct 
substance, although Mulder in his ‘Chemistry of Vegetable and 
Animal Physiology,’ which I have before me only in an English 
translation by Fromberg, without date, regards it as a chemically 
distinct body. When will the time come when chemistry will state 
results on these important substances which will meet with general 
acceptance? It is certain, at all events, that the chemical combina- 
tion of C!2 H!° O!° constitutes a most variable substance. Although 
we may never be able by direct analysis to prove the identity of 
the granular matter in the nectaries, which is coloured brown by 
iodine, and the formula C2 H'° O'°, there is nothing to prevent us 
from assuming the identity, and concluding that the contents of the 
nectary, which are coloured brown by iodine, are isomeric with 
starch. From this substance, therefore, and the nitrogen contained 
in the pollen and ovules, the sugar of the nectar results. 
Cringleford, near Norwich, April 1849. 
On the Intimate Structure of Articular Cartilage. By Dr. Lxipy. 
As is familiar to every anatomist, articular cartilages always 
fracture in a direction perpendicular to their surface, the broken 
edge presenting a striated appearance in the same direction. This 
character the older anatomists ascribed to a fibrous or columnar 
structure of the cartilage, like that of the enamel of the teeth, while 
histologists at the present day consider it as dependent upon the 
vertical arrangement of the rows of cartilage-cells, although it has 
been suspected to depend upon some ultimate arrangement of the 
matrix or intercellular substance not yet detected. in some late 
observations upon the structure and development of articular carti- 
lage, through means of an excellent microscope, made for me by 
* I quote from Mulder’s ‘Chemistry of Animal and Vegetable Physiology.’ 
