The radix linguae of newborn dog contains some lingual follicles with varying number of lymphocyte groups such as never found in the tongues of goat and cat. The purely mucous glands in the submucosa of this part are very well developed and are as distributed as in man. It is of interest that the epithelium here in newborn dog is provided with a considerable number of taste-buds.
Small groups of sympathetic nerve cells contained in the plexus formed here in the propria and the submucosa. These nerve plexus are made of thin vegetative fibres and a rather large number of thick sensory fibres. The former end as always in STÖHR's terminal reticula.
The sensory fibres terminate beneath the epithelium in the propria in and near the follicles, either in unbranched or more often in simple branched terminations formed somewhat more complexly than those in hedgehog, but never in corpuscular endings as found in the human radix of the tongue or in end-bulbs as found in this part of goat. The stem fibres are sometimes thick enough, but more frequently medium in size and the terminal fibres are either thick and subject to change in size or thin and mostly end in sharp points. In some cases the the terminal fibres slightly penetrate into the epithelium to form intraepithelial fibres such as never found in the same part of man or any other mammal examined hitherto.
The taste-buds in the radix linguae in newborn dog are not such degenerated rudiments as they are in man and some mammals, for some of them have fully developed plexiform terminations formed by several fibres just beneath them and some of the terminal fibres frequently form intra- and extra-gemmal fibres.