412 Annales des Sciences Naturelles. 
yellow light. There certainly is some analogy between this light and electricity, 
and it is remarkable that the Photocharis is covered with a glutinous slime, 
which retains its luminous property for a few seconds, after it is detached from 
the animal. Having closely examined twelve species of luminous animals, the 
author comes to the conclusion, that the emission of light is an act dependent on 
their vitality, and which can be repressed or exerted at intervals. Spallanzani 
and others have asserted that parts of Medusa continue luminous after death, 
but Ehrenberg accounts for this by supposing that, when examined, they were 
not really dead. He has often taken up Medusae that had lain for a long time 
on the sea shore, exposed to the sun, and returned them to the sea, and, after 
some time they have recovered, and shewn all the usual signs of vitality. He 
communicated the results of a farther examination of the structure of Medusae, 
(made in 1834) to the Academy, in 1835, but which are not yet printed. 
This volume also contains a paper by the same illustrious naturalist, upon the 
Structure of the Vital Organs, both of Man, and of various Animals. It is illus- 
trated by several plates, containing microscopic representations of these parts, 
in the human body, and in some of each class of vertebrate and invertebrate ani- 
mals. He first describes the microscope by means of which the investigation 
was carried on, and then gives in detail the structure of the brain, the spinal 
marrow, various nerves, ganglions, and sympathetic nerves, and lastly, takes a 
critical view of the observations of other writers upon the same subject. It is 
unnecessary to enter into the details of this paper, as most of them have been 
for some time before the public. They were read to the Academy in 1833, 
and were published in PoggendorfPs Annalen der Physik, Vol. xxviii. 1833, and 
Vol. xxxi. 1834. 
Uber den Bau der Farrnkrduter (on the Structure of Ferns.) Von HERRN LINK. 
Under the general term Fern the author includes the plants belonging to the 
following three divisions : 1st, The Epiphyllospermae, or those whose seeds 
are attached to the back of the leaf, including the Polypodiaceae, Hymenophylleae, 
Osmundaceae, Gleicheniaceae, Marattiaceae, and Ophioglosseae. The 2d division 
contains the Lycopodiaceae, and Salviniaceae, in which the seeds are separated 
from the leaves. The 3d division contains the Equisetaceae. The object of 
the paper is to describe the internal structure of the stems of these classes, and 
the author begins with those of the Polypodiaceae, as a type of the first division. 
They are divided into five classes, Caudex caulescens, C. stolonescens, C. tube- 
rascens, C. arborescens, and C. frutescens. He enumerates several peculiarities 
belonging to this tribe of plants, which are illustrated by two plates of sections, 
and concludes by mentioning several statements, made by writers on botany, 
Mohl, Meyer, Lindley, Cotta, &c. with which his own observations do not accord. 
The paper was read to the Academy in January 1834. 
Annales des Sciences Naturelles. Zoologie, MM. AUDOUIN ET 
MILNE-EDWARDS. Botanique, MM. AD. BRONGNIART et Gu- 
ILLEMIN. Avril 1836. (Continued from p. 292.) 
I. Zoology. 
IN this Number, DUJARDIN continues his interesting " Recherches sitr les or- 
