96G SUMMARY OF CURRENT RESEARCHES RELATING TO 



difficulty is experienced in manipulating it, Lut if the supply of 

 pollen-grains be small, then the contractility of the circular fibres is 

 called into request. These act by diminishing the calibre of the 

 tube, and consequently bring the pollen-grains within control of the 

 lips. The interspace between the chyle and honey stomachs is stated 

 (on account of its formation as a diverticulum and from containing 

 two layers of muscle-fibres) to be intended to prevent the rupture of 

 the organ during the manipulation of honey. 



In this honey stomach the author sees a store-chamber or reservoir 

 of food, which will maintain the animal against hunger and cold for 

 many days, and points out in copious diction the value of this 

 arrangement in winter. 



The author concludes by saying, that if the hand of God turned out 

 the bee at the Creation, then the honey bee and its oesophagus 

 (" Magenmund ") are as they were at the beginning ; if, however, the 

 Darwinian theory be preferred, then in the course of an endless 

 number of years this oesophagus has developed from a folding or 

 constriction of the oesophagus proper (" Speisrohre "). 



Vesicating Insects.* — M. H. Beauregard continues his mono- 

 graph on the Meloideae, discussing in the present contribution the 

 structure of the digestive tube. 



A. External form. — The external characters of the three great 

 divisions are first described. The oesophagus, with thickened and 

 externally ridged walls, exhibits a dilated crop in those forms which 

 do not feed exclusively on pollen. The chylific portion, separated 

 from the former by the cardiac valve, attains a proportionately large 

 size. It is externally marked by annular thickenings of the mucosa. 

 The intestine, separated from the latter by the pyloric valve, is short 

 in those forms which feed principally on pollen, but long and looped 

 in those which live on leaves. 



B. Structure. («) (Esophagus. — Starting with a Cantharid type, 

 M. Beauregard describes the histology of the three oesophageal layers 

 — the chitinous cuticle, the internal longitudinal, and the external 

 circular muscles. Outside the latter the surface of the oesophagus is 

 traversed by fine tracheae enveloped in a mass of irregularly poly- 

 hedral adipose cells, disposed in a hyaline matrix. There is no 

 hypodermic layer between the cuticle and the internal muscular 

 layer. There is no structure which could be interpreted as of the 

 nature of a salivary gland. The labrum exhibits unicellular glands 

 both on its superior and inferior surface. The internal muscular layer 

 consists of striated longitudinal muscles disposed side by side in a 

 kind of membrane. The external muscular layers include two or three 

 planes of superposed circular fibres. The cuticle is a chitinous trans- 

 parent layer, raised internally in numerous hair-like prolongations, 

 which are regularly disposed in rows. The ventral region is free 

 from these processes. Three projecting folds form two parallel 

 grooves with transverse linear thickenings. Lastly, the valves formed 

 by a prolongation of the oesophagus into the chylific portion, are 



* Journ. de l'Anat. et de la Physiol, xxii. (1S36) pp. 242-S4 (4 pis.). 



