96 QUARTERLY CHRONICLE. 



" Contributions to a Knowledge of the Structure of the Taste- 

 2JapiU(B of the Tongue," by Dr. Christian Loven. Translated 

 from the Swedish. — This is an important histological memoir, 

 illustrated with a plate. 



" The Hearing-organ of the Stag-beetle'' (Lncanus cervus), 

 by Dr. H. Landois (figs. 4, 5^ 6). — There is no insect in which 

 the nerves of the head can be more beautifully or more readily 

 prepared than the Stag-beetle. The nerves are particularly 

 large in relation to the brain, and may be well dissected under 

 spirit. The antennary nerve is very large, and by slitting 

 up the antenna it may be traced even to the last joint, in the 

 cavity of which it gives rise to a peculiar structure. If the 

 terminal bit of the antenna of the stag-beetle be examined, 

 even with the naked eye, a small point-like depression can 

 be detected both on the under and upper surface. These 

 pits occur in male and female specimens both, varying 

 only with the size of the antenna ; they occur only on the 

 terminal -joint, which has a peculiar shape, like that of 

 the sole of a boot. The pits are seen, with a magnifying 

 power, to lead into the inside of the antennal plate. Cross 

 sections and a solution of concentrated nitric acid and 

 chlorate of potassium are used in the further investigation. 

 The aperture of the pits is somewhat circular, and internally 

 they have a pitcher shape. The whole plate-bit or joint is 

 covered externally with hairs, which are of two sorts — small 

 and large. They are all short and thick proportionately, and 

 the large ones, which are fewest in number, are seen to be pro- 

 vided with a swollen knob-like base. The integument presents 

 two chitin-layers, of which the inner is rendered separable by 

 the treatment with acid. The outer is excavated by large 

 pitcher-shaped canals, from which the hairs emerge. Beneath 

 lies the hypodermis of rounded nucleated cells. Three or 

 four expanded tracheal vesicles lie in the middle of the 

 terminal-joint, connected with the general antennary trachea. 

 The nerve, Avhich is the important thing in this organ, enters 

 it as a single stem of some thickness, which then splits up 

 into three or four branches spreading out in the " plate.^'' 

 The nerve and these branches are covered with a conspicuous 

 neurilemma, in which are many nuclei. Fine twigs proceed 

 from the branches in every direction towards the surface of 

 the organ, devoid of a neurilemma. The end-organs of these 

 branches are very peculiar. Each nerve-twig on reaching 

 the hypodermis gives rise to a large oval ganglion-cell, wliich 

 lies just below the chitinous layer, and corresponds in position 

 to one of tiie flask-shaped canals from which the hairs of the 

 surface emerge. The ganglion-cell is continued up into this 



