4 
In this communication I shall only attempt to describe 
briefly those points which I believe to be new, and which are, 
I conceive, demonstrated in my specimens for the first time. 
Most of the points described in this paper were demonstrated 
in 1862, and the specimens have been repeatedly studied and 
shown to other observers. The points described could still be 
demonstrated in the same specimens in June, 1864. 
The structures entering into the formation of the papilla 
are the following : 
1. The connective tissue which forms the body of the 
papilla. 
2. The “ epithelium.” 
3. The nerve-fibres in the body of the papilla, and the 
fibres prolonged from them which form a plexus upon 
its summit. 
4. Nerve-fibres ramifying in the connective tissue, upon 
the capillary vessels and amongst the muscular fibres. 
5. The muscular fibres. 
6. The vessels. 
The Connective Tissue. 
The nerves, vessels, and muscular fibres are embedded in a 
very transparent basis-substance which exhibits a slightly 
striated or fibrous appearance when stretched, but this struc- 
ture in all the papillae of the Hyla is exceedingly delicate and 
transparent. 
The great majority of the masses of germinal matter (nuclei) 
seen in this basis or connective substance are undoubtedly con- 
nected with the nerves, vessels, and muscular fibres, but there 
are a few which seem to belong to the connective substance 
alone, and may therefore be called “ connective-tissue cor- 
jmscles .” It is possible that these at an earlier period may 
have been connected with nerves or muscles ; at any rate, 
they are the descendants of the same nuclei or masses of ger- 
minal matter as the nuclei taking part in the production of 
these tissues. 
I consider that indefinite connective tissue of this kind 
results principally from the accumulation of the remains of 
higher structures, especially nerve-fibres, which were in a 
state of functional activity at an earlier period of life. At an 
early period of development nuclei (masses of germinal mat- 
ter) can alone be detected. As development proceeds, tissue 
is formed by these nuclei, and increases as age advances. The 
large and fully-formed fungiform papillae have twice as many 
nerve-fibres as smaller and younger ones. During the 
development of such an organ as one of these papillae many 
