SCIENTIFIC SUMMARY. 
117 
the perfect insect ; they would be concealed by the wings, and the diffusion 
of the odour could not occur. 
On the Development of Small Acari in Potatoes. — M. Guerin de Menne- 
yille exhibited at a late meeting of the French Academy some specimens 
of potatoes covered with acari, but appearing to be perfectly sound. M. 
Guerin Menneville remarked that the late two months of wet weather had 
produced myriads of acari, known as Tyroglyphus feculce, on the Australian 
and other varieties of potato growing on the Imperial farm at Vincennes. 
It seems at present uncertain whether this immense crop of acari is the 
consequence of the disease in the potato, or the more or less proximate 
cause of a change in the tubercle, which will eventually manifest itself. 
Beproduction of the Limbs in the Newt. — M. Philippeaux has been per- 
forming some experiments with the view of ascertaining whether the limbs 
of newts, if completely extirpated, would be regenerated. He found in 
numerous instances that when he extirpated the scapula, there was not 
the slightest sign of regeneration. On the contrary, when M. Philippeaux 
amputated the limb, leaving the basilar portion, it was entirely reproduced, 
with all its osseous portions. Experiments of the same nature on fishes 
have had a similar result, and M. Philippeaux deduces as a general fact, at 
least amongst the vertebrata, that no organ will grow again unless a portion 
remains in its place. 
On the Structure of the Cornea in Peptiles. — Dr. Lightbody, taking the 
tortoise as a type, gives the following account of the structure of the cornea 
of the tortoise. It is between that of mammals and fish 3 the lamellae are 
thin and well marked, the corpuscles small and few, but pretty regularly 
scattered through the whole thickness. The bundles are very broad, and 
have almost lost their individuality, blending with their neighbours by their 
margins. They are also arranged, as in birds, at right angles to those that 
occur immediately above and below them. The corpuscles are fusiform, 
and are arranged principally in two directions, one at right angles to the 
other. The sensor nerves are very large and strong, with the cells well 
marked and pretty numerous. — Vide Journal of Anat. Phys., No. 1. 
The Nerves in Insects. — In the last number of the Microscopical Journal 
Dr. Moxon describes the arrangement of the nervous system in the larva of 
a species of water-gnat. He opposes Dr. Lionel Beale’s views in the 
strongest terms, alleging that the nerves by no means end in delicate reticu- 
lations, but, as M. Kuhne asserts, end in distinct solid cones or masses. The 
nervous fibres, he states, end in the nuclei on the surface of the sarcolemma. 
It seems to us, however, that an important objection may be raised to Dr. 
Moxon’s views in the fact which he himself adduces, viz. that the larvae in 
which he saw this arrangement of the nuclei most distinctly were those 
which had been reduced to what he calls a dropsical condition by forty-eight 
hours’ confinement in airless water. Dr. Beale’s observations have shown us 
that, in order to look for the terminations of the nerve fibres, we must take 
the larva and prepare specimens from it at the moment of its death, and 
examine them without delay. Dr. Beale did this at the time of the Croonian 
lecture to the Itoyal Society, and he then demonstrated satisfactorily that 
the nerves do not end, so to speak, but form numerous extremely delicate 
fibres^ which are arranged in a complete network. 
