300 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
Rectum and Rectal Glands of Orthoptera.* * * § — M. L. Bordas has 
studied the structure of these parts in forty species belonging to diverse 
families. There is great uniformity. The rectum is an ovoid rect- 
angular or fusiform region, with thick musculature, and six glandular 
ridges parallel to the longitudinal axis. In Forficulidse the glands are 
somewhat divergent, being spherical and disposed in two alternating 
tiers. As in Hymenoptera, these glandular ridges consist of groups of 
unicellular glands. 
Segmental Glands of Ocypus.f — Dr. Jivoca Georgevitsch has 
studied the integumentary glands on the young stages of the Staphy- 
linid Ocypus olens Mull. He distinguishes the more regular segmental 
glands from others which he calls globiform. Of the former there are 
14 pairs, one in the head, three in the thorax, and ten in the abdomen. 
Each consists of a large number of digitate glandular tubes. While the 
segmental glands occur both on larvae and embryo, the globiform glands 
seem to be exclusively embryonic. Apart from the head, each segment 
has normally four globiform glands, each consisting of a giant glandular 
cell. As both sets of glands appear to he ectodermic, there is no warrant 
for comparing them with the nephridia of Annelids. 
Articular Membranes in Hymenoptera.J — M. Charles Janet has 
made a careful study of the articular membranes and the morphological 
limits of the segments in adult ants ; but his results are not readily sum- 
marised. The articular membrane is situated in the vicinity of the 
morphological boundary between two segments, but almost entirely on 
the relatively less mobile segment. Thus the prothoracic and meso- 
thoracic segments in ants bear their articular membrane towards the 
anterior border, while the post-thoracic segments bear their articular 
membrane towards their posterior border. 
Taxonomic Value of Hervures.§ — Dr. A. Griffini, after describing 
the wings of Haliplidee ( Cnemidotus and Haliplus), notes that the taxo- 
nomic value of the nervures in Coleoptera is not great. In Dytiscidae, 
for instance, the disposition of the nervures changes from genus to genus. 
Thus, as to nervures, Hydroporus differs from Dytiscus and Acilius , and 
the two last differ from the Haliplidee, while Dytiscus , Gybister , and 
Acilius are identical with Calosoma among the Carabidse. 
Changes in Structure of Butterflies’ Wings.|| — Mr. A. Radcliffe 
Grote finds that the changes in the veins of the wings, as deduced by 
comparative study, ‘ take a direction which stands probably in relation 
to the mode of flight, and that the processes themselves may be distin- 
guished as follows : — firstly, the reduction by absorption of the radial 
veins ; secondly, the disintegration of the median series ; and thirdly, 
the reduction and suppression of veins above the radius and below the 
cubitus.” The changes appear to have their origin in the hind wings, 
on which there is a greater strain in flight. 
* Comptes Rendus. exxvi. (1898) pp. 911-2. 
t Zool. Anzeig., xxi. (1898) pp. 25G-61 (4 figs.). 
X Comptes Rendus, exxvi. (1898) pp. 435-9 (3 figs.). 
§ Ex Miscellanea Entomologica, No. 9, 1897 (2 pp., 2 figs.). 
|| Trans. Entomol. Soc. London, 1897, pp. 333-42. 
