288 SUMMARY OF OUKRENT KESEAKCHES RELATING TO 



Intracellular Fibrillation in Tunic of Salivary Glands in Larval 

 Syrphids.*' — 1). Keiiiii finds around the salivary glands — which are 

 strongly developed in Syrphid larvae — a well-marked fibrillar tunic. 

 The fibrils are intracellular differentiations. It is probable that the 

 layer in question is an exaggeration of the delicate tunica propria which 

 occurs around the salivary glands in many insects. 



Wing-veins of May-flies. j — Anna Haven Morgan has shown that 

 the main veins of May-flies may be homologized with the veins of 

 insects of other orders. The main trachea precede and constantly 

 mark the course of the main veins. The costal and suljcostal tracheae 

 are simple and parallel as are the veins which follow them. The radial 

 tracheae (except in one form studied) and the vein which follows it are 

 unbranched. The tracheal system enters the wing by a single stem. 

 The course of the cubito-anal trunk shows a possible trace of the 

 double stem of the tracheal system of other orders. In the series of 

 wing-pads studied a remarkable evolution of tracheation is shown — 

 a gradual reduction of main trachea? and replacement by small 

 branches. 



Structure and Metamorphosis of Fore-gut of Corydalis cornu- 

 tus.J — R. Matheson describes the pharynx with its dilator muscles, the 

 oesophagus with its numerous longitudinal folds, the gizzard (with its 

 interlocking chitinous teeth) which has a grinding and crushing action 

 as Avell as a straining function. It does not pass directly into the region 

 called " the oesophageal valve," but is joined to it by a short more or 

 less thin tube. The oesophageal valve is short and is lined with four 

 strongly chitinized ridges which alternate with the c^ca. At the point 

 of union of the epithelium of mid-gut and fore-gut there is a peculiar 

 group of glandular cells of doubtful function. 



The metamorphosis of the fore-gut is of a generalized type. The 

 larval epithelium becomes partially broken down and the cells destroyed 

 are replaced by the division of rejuvenated larval cells. The nuclei 

 always divide mitotically, and every spindle is located at the side of a 

 vacuole. The dividing cell migrates towards the inner surface, though 

 it retains a connexion with the Msement membrane. The muscles 

 liquefy in place. Most of the larval nuclei become rejuvenated and 

 around them as centres the new fibrillar structures are developed. The 

 rule of the leucocytes is comparatively unimportant. They engulf small 

 particles of the broken down tissues, but they do not take any active 

 part in breaking down the muscles or the epithelium. 



7. Prototracheata. 



American Species of Peripatus.§— A. H. Clark reports the interest- 

 ing discovery of Peripatus {Macroperqmttis) geayi Bouvier in Panama, 

 previously only known from French Guiana, and Peripatus {Perq)atus) 

 jaanemis Bouvier from a small island oft' Porto Ptico, also a new 

 locality. 



* Comptes Rendus, clvi. (1913) pp. 908-JO (5 figs.). 



t Ann. Entomol. Soc. America, v. (1912) pp. 89-106 (5 pis. and 6 figs.). 



: Jourii. Morphol., xxiii. (1912) pp. 581-615 (4 pis.). 



§ Smithsonian Misc. Coll., Ix. No. 17 (1913) pp. 1-5. 



