376 SUMMARY OF CUERENT RESEARCHES RELATING TO 



Olfactory Structures in Insects.* — E. W. Roberts calls attention 

 to the rich innervation of the epidermis in insects. Sensory cells of a 

 generalized type are very common. Some fibrils within the cell arise 

 directly from small bodies in the outer end of the cell, which in their 

 turn arise from division of the centrosphere. Other fibrils lie in the 

 walls of the cell in the chitin matrix. Their terminals are always 

 naked and exposed, no matter how heavy the chitin may be around 

 them. 



The sensory cells of the epidermis may be sunk below tlie surface, as 

 in Hicks' vesicles, or compounded into pore-plates beneath or flush with 

 the surface, or raised into variously formed spines, scales, hairs, and 

 pegs. But the general structure remains the same as that indicated 

 above. The author's conclusion is that many types of epidermal cells 

 widely scattered over the Ijody are normally susceptible to olfactory 

 stimuli. 



Elytral Tracheation of Tig-er-beetles.t — V. E. Shelford has made 

 a comparative study of the tracheation in the elytra of a large number 

 of Cicindelidffi. The two walls of the sac-like elytron are held together 

 by chitinous pillars or columns. Setas are almost always present, and 

 the elytra of many species are marked by pits which are usually over 

 the centre of the chitinous columns. There are sometimes thickenings 

 running lengthwise of the elytron (as in Domica), and whila these run 

 parallel with the trachea they are usually between lather than coincident 

 with them (except in Caledonica). The six main tracheal trunks 

 common in insects are represented in but two genera {AmblychUa and 

 Mantichora), whicli have rudimentary wings and specialized elytra 

 fastened together in the adult. The peculiarities of the different groups 

 of the family as regards tracheation of the elytra are briefly stated and 

 fully illustrated. There is in the family as a whole a tendency to 

 reduce the anal. It is shown conclusively that tracheation is far from 

 haphazard, but of more or less constant taxonomic significance. 



Larvae of Furniture-beetles.J — James W. Munro has done a very 

 useful piece of work in describing and contrasting the larvse of the 

 furniture-beetles. They belong to the two families Anobiida3 and 

 Lyctida^. Of the Anobiids four or more species are more or less 

 common in houses and other buildings — Anohmm domesticum and 

 PtiJimis pectinicornis, most commonly found in furniture ; A. paniceum, 

 in stored goods ; and Xestobium Uneatum, in heavier timbers, e.g. rafters. 

 A fifth species, Ernobius mollis, is rarely found indoors, but the author 

 has two records from spruce flooring-boards and from old rafters. It is 

 usually found under the bark of large paling posts or other coniferous 

 timber. The family Lyctidte includes Lyctus canaliculatus and 

 L. brunneus, both found in stored timber, furniture, and in walking- 

 stick and umbrella handles. 



The larvse are well adapted to their hfe. They are soft fleshy 



* Trans. Amer. Micr. Soc, xxxiv. (1915) pp. 284-90 (6 figs.), 

 t Trans. Amer. Micr. Soc, xxxiv. (1915) pp. 241-52 (6 pis.). 

 J Proc. Roy. Phys. Soc. Edinburgh, xix. (1915) pp. 220-36 (2 pis. and 9 figs.). 



