ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 41 



-certain colour tend to return to it habitually. They exhibit colour 

 fidelity ; but this habit does not become obsessional, since they quickly 

 learn to discriminate between colours when this is for their advantage. 



Scelionid Parasite of Spider's Eggs.* — E. Bugnion and N. Popoff 

 describe Baeus apterus sp. n., a small apterous Hymenopteron, allied to 

 the Proctotrupidae, which lays its egg in the egg of a Ceylonese spider, 

 Argyope setherea Walckenaer. The parasite develops in about 12 to 13 

 days, which corresponds to that of the spider (14 to 15 days). The male 

 insect is winged ; and the authors note the curious point that in Oophthora 

 semblidis Aur., studied by Silvestri, it is the male that is apterous, while 

 the female is winged. 



Nervous System of Dytiscus marginalis.| — Georg Holste gives a 

 full and well illustrated account of the macroscopic features of the 

 nervous system of this beetle. The nerves of the thorax and abdomen 

 are thoroughly worked out and named for the first time. Attention may 

 also be directed to the analysis of the sympathetic nervous system — the 

 ganglia and nerves of the gut, the dorsal blood-vessel, and the tracheae. 



New Termitophilous Staphylinid.J^F. Silvestri describes Termi- 

 toptochus indicus g.etsp.n. from Singapore termitaries {E titer mes singa- 

 porensis Havil.). It is allied to Termitomimus Trag., but is very distinct. 

 The female has an elongated body, with a triangular inflated abdomen 

 turned upwards and forwards, so that sternites 2-6 are posterior and 

 dorsal. 



Eye of Dermestes.§ — 0. Kirchhoffer has studied the development of 

 the eye in this beetle. The conical ingrowths of the cornea (corneal 

 processes) cannot be regarded as crystalline cones which have fused with 

 the cornea. The crystalline cones are intra-cellular structures due to 

 " Semper's cells," and they are not developed in Dermestes vulpinus. The 

 corneal processes are extra-cellular products of " Semper's cells," which 

 lie in the imago between the corneal processes and the retinula. 



In the formation of the cornea a part is played to begin with not 

 only by " Semper's cells," but also by the main and the accessory pigment- 

 cells. The corneal processes are formed in the same way as the cornea 

 proper. 



The retinula consists primarily of eight cells, of which one is central, 

 while seven are peripheral. By the coalescence of the peripheral cells 

 the central cell is compressed down to its nucleus. 



The pigment is not a product of the cells in which it occurs in the 

 imago. It arises from the pigment of the larval eyes, which retreat 

 during metamorphosis towards the optic ganglion. The pigment-granules 

 migrate along the post-retinal fibres, first into the retinula cells and then 

 into the pigment-cells. 



Intestinal Secretion in Dytiscus. || -Deegemr describes what goes 

 on in Macrodytes {Dytiscus) circumcinctus, and compares the process with 



* Rev. Suisse Zool., xviii. (l'JIO) pp. 729-38 (1 pi.). 



t Zeitschr. wiss. Zool., xcvi. (1910) pp. 419-7f (12 figs.). 



t Boll. Lab. Zool. Scuolo Agric. Portici, v. (1910) pp. 37-9 (3 figs.). 



§ Arch. Natur.. lxxvi. (1910) pp. 1-26 (2 pis. and 7 figs.). 



|| Tom. cit., pp. 27-43. 



