156 
REPORT ON ZOOLOGY, MDCGCXLII| 
thorough knowledge and the greatest care. The book has been written 
for a wide circle ; and while thus, on the one hand, it contains much 
which is only subservient to introducing the subject to general readers ; 
on the other, it is rich in valuable information on the habits of North 
American Insects. As this work is probably but little known in Europe, 
I shall, in the course of this report, frequently draw attention to it. 
The entomological portion of D’Orbigny’s voyage, which had been in- 
termitted for several years, has been renewed by Blanchard, and carried 
on with more research than his predecessor devoted to it. The text 
lying before us, reaches to the end of the Clavicornia. The plates are 
in advance, but they cannot be here noticed until the descriptions have 
also appeared. 
The zoological portion of the Voyage autour du Monde, 1836-37, 
sur la Corvette Bonite, par M. Vaillant, Paris, 1841-42, is not yet 
accessible to me, so that a report upon it must be postponed. 
COLEOPTERA. 
Herrm. Meyer lias analyzed the horny shell of Beetles. 
(Miill. Archiv. f. Anat. und Phys. 1842, p. 12.) 
In order to remove from it the brittleness, which renders fine sections 
for microscopical research impossible, it is necessary to soften it for a 
long time in caustic potass. By this means an epidermis on both sides 
is removed, which is formed of one simple layer of cells, placed in rows 
next to each other. The internal epidermis is very thin, the walls of its 
cells are recognised with difficulty, and instead of the usual included 
substance, each cell has a spicula rising up obliquely in the middle of it. 
The middle portion of the horny shell is composed of small longitudi- 
nal fibres, which are united in layers by simple apposition, of which 
a greater or lesser number are joined together in order, so that the 
directions of the fibres of each layer cross at angles of 45° or 90°.* As 
to whether any peculiar connecting substance exists between the small 
fibres, the author is still doubtful. Between the external epidermis, and 
* The original of this difficult passage is added. 
Es lasst sich darauf an beiden Seiten ein Epidennisiiberzug ablbsen, der 
aus einer einfachen Schicht neben einander gereihter Zellen gebildet wird. 
Die inner Epidermis ist sehr diinn, die Granzen ihrer Zellen sind schwer zu 
erkennen, und statt der kerns hat jede Zelle einen shragen stachel, der sich in 
ihrer Mitte erliebt. Der mittler Theil der Hornschale ist aus Stabchen zu- 
sainniengesetzt, welche durch Nebeneinanderlegung und Anastoniosiren zu 
Schichten vereinigt sind, deren nach Unstanden eine grbssere oder geringere 
Zahl aufeinandergefugt sind, so das die Richtungen der Stabe der einzelnen 
Schichten sich unter Winkeln von 45 oder 90° kreuzen. 
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