THE GENERAL SUBJECT. 
Ins. 3 
of Xenos vesimrum examined), the head portion of the nerve-system is 
peculiar, consisting merely of a supra- oesophageal ganglion, the infra- 
oesophageal being wanting, as in Rhizotrogus solstitialis and Serica brunnea 
in Coleoptera, and Hydrometra lacustris in Hemiptera. The thoracic part 
consists of one large complex ganglion divided into two portions, the 
anterior smaller, representing the infra-oesophageal ganglion and first 
thoracic knot of other insects, the posterior equivalent to the normal two 
other thoracic knots and the more or less numerous abdominal ganglions. 
The forward part supplies nerves to the mouth and first pair of legs — 
the posterior to the wings, remaining legs, thorax, and some abdominal 
segments. The abdomen has one nervous knot, supplying the fifth, sixth, 
and apical segments, and the rectum. 
The “ Lamellicorn ” beetles observed include Lucanidm as well as 
Scarahceidce (30 species of 19 genera) ; and the results so far agree with 
those of former observers as to justify the two great type-forms of 
genuine Lamellicorns with no abdominal ganglion, and Pectinicornia with 
from five to six of them. No absolute connecting links are found, but 
the genuine Lamellicorns are divided into 7 typical groups, repre- 
sented by Rhizotrogus, Serica, Phyllopertha and Anomala, Cetonia and / 
Melolontha and their immediate allies, Oxythyrea, Geotrupes and 
Copris and allies, and Glaphyrus, in the last of which the last of 
six knots representing the abdominal ganglion is situated in the first 
abdominal segment, thus showing an approach to Lucanus . The nervous 
systems of the larvre and pupoo of species of both groups are described, 
but apparently with no result differing especially from those obtained by 
former observers. 
In the Hemiptera, Brandt has examined the systems of 170 species 
(including Homoptera and Anoplura), and he gives a list of the prior 
works on the subject. Only cephalic and thoracic ganglions are found ; 
the supra-cesophageal is always strongly developed ; and in every one of 
the species examined, the author found the brain convolution bearing 
stalked bodies hitherto only noticed in Acanthia lectularia. Several 
species have ocellar nerves ; the infra-oesophageal gland exhibi ts greater 
variability than is shown in any other Order of Insects ; the supra- 
cesophageal is wanting in very few species, and has special morphological 
value, &c. Five type-forms are recognized, represented by Hydrometra, 
Nepa and Acanthia, Pentatoma, Lygeeus, and the Anoplura with the 
Mallophaga. The entire want of abdominal ganglions places the Hemi- 
ptera with the Muscce acalypterm and (Estridee, but also associates the 
Order with such of the beetles {LucanidcB, Gurculionidoe, &c.) as are also 
deficient in that respect. 
Brauer, F. Betrachtungen fiber die Verwandlung der Insecten im 
Sinne der Descendez-Theorie. ii. Verb. z.-b. Wien, xxviii. [for 1878, 
published in 1879], pp. 151-166. 
A continuation of the author’s former treatise [Zool. Rec. vi. p. 173] 
on the same subject, with corrections on some points. 
Brischke, G. Resultate der Zuchten forstschadlicher Insecten. Schr. 
Ges. Danz. (4) ii. pp. 4. 
