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PROGRESS OF MICROSCOPICAL SCIENCE. 
The Structure of the Bods of Gorti. — Dr. Urban Pritchard has com- 
municated a short but important paper on this subject to the Royal 
Society, May 30th, from which we may give the following account of 
these curious rods : — In a general view of the rods from above, they 
appear similar to two rows of pianoforte hammers, rather than like 
the keys of that instrument, to which they have been likened. In a 
lateral view, these two rows of rods are seen sloping towards each 
other, like the rafters of a gabled roof. The rods consist of a shaft 
and two enlarged extremities, but the two rows differ considerably in 
form ; the inner rods are attached by their lower extremities to the 
membrana basilaris at its junction with the lower lip of the limbus, 
and just external to the spot where the nerve filaments emerge ; they 
are directed outwards and upwards, with a slight undulation to meet 
the outer rods. The lower extremity is enlarged and rounded, gra- 
dually tapering to the shaft, which is cylindrical ; the upper extremity 
is somewhat cuboid in form, but the outer surface is deeply concave, 
and the upper lip of the concavity is prolonged into a process. The 
outer rods are attached to the membrana basilaris by a broad base, 
which also gradually tapers to a cylindrical shaft. Their upper ex- 
tremity is less cuboid in form, and presents a convex internal surface, 
which articulates with the corresponding concavity in the inner rods 
just mentioned ; from the outer and upper part there extends outwards 
a slender process. One of the most important features with regard to 
these rods is their relative length. Most authors state that there is 
very little difference in the length of the two rods ; in this, however, 
they are much mistaken ; for not only do the two sets of rods differ in 
this respect, but the length of each varies according to its position on 
the cochlea. Thus, at the base, the outer rods are as nearly as pos- 
sible equal in length to the inner ; but proceeding upwards, both rows 
increase in length with great regularity, although not in the same 
ratio, the outer increasing with much greater rapidity, so that near the 
apex they are twice the length of the inner. It was generally sup- 
posed, a priori , that these rods, were graduated so as to distinguish the 
most minute variation of tone, but no one until now has been able to 
demonstrate this. The rods, therefore, vary in length from about 
5^0 to °t an Atch. The number of rods in each row is not the 
same, there being about three of the inner to two of the outer ; and, 
according to calculation, there are about 5200 inner rods and 3500 
outer in the whole cochlea. Most authors, with the exception of 
Deiters, describe nuclei situated in various parts of these rods, prin- 
cipally in the lower extremities ; but although seen from above this 
appears to be the case, on closer observation these so-called nuclei of 
the rods are found to be nothing more than the nuclei of cells sur- 
rounding them. 
The Early Stages of the American Lobster (Homarus Americanus ). — 
These are the subject of an able paper of some length in the June 
