THE GENERAL SUBJECT. 
Ins. 11 
Anatomy, Physiology, &c. 
See also Bobretzky, Brandt, Dewitz, Flogel, Graber, Haller, 
Joseph, Kroger, Lowne, P^irez, Schindler, & Simroth, supra, 
Ovology. A. Brandt’s work “ Ueber das Ei und seine Bildungstatte ” 
(Leipzig : 1878, pp. 200, pis. i.-iv.) contains an elaborate account of the 
insect ovary, egg-structure, and genital organs, with a special comparison 
of the component parts of the egg in Insects with those of other classes. 
Tracheal-system as basis of Classification. Ernst Voges, Z. wiss. Zool. 
xxxi. pp. 143 & 144, in “Beitrage zur Kenntniss der Juliden” \_Myrio- 
poda^ supr^], gives the following scheme for the Tracheata : — 
A. Tracheal openings fasciculate, tracheae non- branchiate, on a free 
upper surface, without metameric arrangement, principally 
situated on the ventral and lateral surfaces. 
a. Tracheal openings irregularly distributed over the sur- 
face . . . . . Peripatus capensis. 
h. Tracheal openings distributed so far with regularity that 
the majority are placed in two lateral rows, alternating 
with the 15 pairs of foot-stumps of the animal. 
P. novce-zealandice. 
B. Openings fasciculate, tracheas non-branchiate, on a covered upper 
surface, with metameric arrangement, and situate on the ventral 
surface of the body. 
c. Openings irregularly disposed over the upper surface of the 
integumentary covering . Polydesmus complanatm p. 
d. Openings regularly disposed over the upper surface of the 
integumentary covering . Spiroholus cupulifer, Julus 
londinensis. 
C. Openings of dissimilarly formed tracheae on a free upper-surface, in 
the majority with metameric arrangement, situate on the ventral 
or lateral surfaces, and becoming a more uniform organ-system 
by fusion of contiguous branches. 
e. Tracheal openings not placed metamerically, with fascicu- 
late, non-ramose tracheae, having cribriform orifices 
ramose tracheal stems with simple orifice occurring in 
the same animal . . Gihocellum {Arachnoidea). 
f. Tracheal openings arranged metamerically, cribrose and 
simple-mouthed tracheae in the same genus, but occur- 
ring in different forms . . . Scolopendra. 
g. Tracheal openings arranged metamerically, tracheae with 
arborescent ramifications, anastomosing, joined before 
the opening to a rudimentary trachea . . Insecta. 
B41a Deszo, in Zool. Anz. i. p. 275, discussing the connection between 
the circulatory and respiratory organs in the Arthropods remarks that 
in Insecta^ Arachnida, and Myriopoda there are as many pairs of open- 
ings in the dorsal vessels as there are pairs of stigmata. 
Respiration. Chemical experiments by R. Pott (Landwirthschaftliche 
Versuchsstationen, xviii. 1875, p. 81), with table showing the amount of 
