8 Ins. 
INSECTA. 
M‘Alpine, D. a Zoological Atlas (including Comparative Anatomy) 
with Practical Directions and Explanatory Text. For the use of 
Schools. 249 coloured figures and diagrams. Pt. ii. Invertebrata. 
Edinburgh and London : 1881. (Cf. Nature, xxv. pp. 122 & 123.) 
McLachlan, R. Insects. Encyclopajdia Britannica, 9th edn., xiii. 
pp. 141-154. 
About half this paper is devoted to habits, structure, and other general 
matter, and the remainder to classification. 
. Notes on the Insects collected by A. H. Markham (in Novaya 
Zemlya). Markham’s “ Polar Reconnaisance ” (London : 1881, 8vo), 
pp. 350-352. 
Notes on Hymenoptera (1), Coleoptera (1), Lepidoptera (7), Trichoplera 
(1), Diptera (9), and Mallophaga (1). 
MacLeod, J. Concours universitaire de 1878-79. Question de Zoologie. 
Memoire Couronne. La Structure des Trach^es et la Circulation 
peritracheenne. Bruxelles : 1880, 8vo, pp. 72, pis. iv. (c/. Am. Nat. 
xiv. pp. 213 & 214). 
The following subjects are discussed : — Structure of the tubular 
tracheae, tracheal vesicles, interstigmatic-masses (manchous), leaf-like 
tracheae of Araneidce and Scorpionides, and analogous organs; Relations 
of the tracheae to the tissues in which they are embedded, and mode of 
their termination ; Theory of peritracheal circulation ; Bibliography. 
The author’s conclusions have been derived from the examination of a 
considerable number of insects and other Articulata tracheata. He sums 
up his principal results in the following eight theses : — The wall of the 
trachea consists of three layers, an outer layer, probably connective, a 
middle chitin-forming, and an internal chitinous layer. (2) The spiral 
thread does not properly belong to the tubular tracheae. (3) The spiral 
thread does not differ from the rest of the intima in thickness only, but 
more especially in its properties. (4) The tubular tracheas, and espe- 
cially their intima, exhibit numerous variations, even within a special 
group, such as that of the insects. (5) The chitin-forming tunic of the 
trachea is not formed by cells fused together, but is a true epithelium. 
(6) The intermediate layer remains independent along the whole length 
of the trachea. (7) Peritracheal circulation is anatomically impossible. 
(8) In many larvfe, the intima exhibit other portions besides the spiral 
thread, differing in their properties. 
Macloskie, G. The Endocranium and Maxillary Suspensorium of the 
Bee. Am. Nat. xv, pp. 353-3G2, figs. ; P. Am. Ass. 1880, 
pp. 660-666, figs. 
The chitinous wall which covers an insect’s body is folded inwards or 
outwards into processes which impart additional strength or protection, 
or for the attachment of muscles. The outgoing plates, or exodemes, 
have their counterparts in the internal processes (or endodemes), which 
are more or less hardened in particular parts, thus forming an endo- 
skeleton, which is best developed in the ventral part of the thorax, and 
where it forms the endocranium, or internal buttresses of the skull. The 
hard processes of the pharynx and stomach may be collectively termed 
