ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 17l> 



Paessler, and others. It is satisfactory to have a number of collections of 

 similar material dealt with at once. Fourteen new species are described ; 

 and the growth-changes and variations of Trophon geversianus are deali 

 with in detail, with abundant illustrations. 



Arthropoda. 



Insertion of Muscles on the Skeleton of Arthropods.* — R. H. 

 Stamm has made a precise study of the way in which the muscle fibres 

 become attached to the chitinous skeleton in insects and crustaceans. 



a- Insecta. 



Sense of Hearing in Insects.! — Em. Radl maintains that the sense 

 of hearing exists in insects, but on a simpler basis than in higher verte- 

 brates. The structural and functional basis is not to.be looked for in the 

 tactile organs, of which there are many sorts, but in the chordonotal 

 organs which are in close association with muscular activity. Hearing 

 in insects is a refined muscular sense. 



Development of the Gut in Insects during Metamorphosis. 1 — 

 P. Deegener has elucidated the following facts from a studv of CyMster 

 roeselii Curtis. The mid-gut epithelium of old larva? is thrown off at 

 the time of its transformation into the pupa, and is replaced provisionally 

 by a " KryptmJials-epithel." This provisional epithelium is soon pushed 

 into the gut lumen, and, with the remains of the active epithelium, forms 

 the " yellow body " of the larva. The larval basal membrane is preserved 

 during these changes. In the later stages of the larva an epithelium 

 peculiar to the pupa is developed, whose function is limited to the 

 "yellow body" of the larva. The pupa epithelium is built up of the 

 imaginal cells of the larval " Kryptmschl&whe" and towards the fourth 

 day of the pupal period it approaches dissolution. Subsequently the 

 pupa epithelium, along with the larval basal membrane, occupies the inner 

 region of the imaginal mid-gut, whose wall is formed of imaginal cells. 

 This epithelium, which is separated from the imaginal islands, forms the 

 " yellow body " of the pupa. An analogous shedding of the epithelium of 

 the other regions of the gut, and also of the gut musculature takes place. 



Wax-glands in Meliponidse.§ — L. Dreyling concludes, from a study 

 of the structure and development of these glands in Melipona quinque- 

 fasciata, that they are fundamentally similar to those of the honey-bee, 

 and are to be distinguished from these only by their dorsal position. 



Hypopharynx of Hymenoptera.|| — Max Hilzheimer has studied the 

 " hypopharynx " of Hymenoptera, which is never rudimentary as in 

 many other insects, e.g. Coleoptera, but is often so strongly developed 

 that it can bear masticating organs, as in Thysanura and Poduridre. As 

 regards the hypopharynx, the Hymenoptera represent an early divergence 

 from the primitive insect stock. 



• Mem. Acad. Roy. Danemark, Copenhagen, 7th series, i. pp. 127-64 (2 pis.). 



f Biol. Centralbl., xxv. (1905) pp. 1-5. 



% Zool. Jahrb. (1904) xx. pp. 499-676 (11 pis.). 



§ Zool. Anzeig.. xxviii. (1904) pp. 204-10. 



I Jenaische Zeitschr. f. Naturwiss., xxxix. (1904) pp. 119-50 (1 pi.). 



