[254] 



IReview* 



The Polyclinic: a Monthly Journal of Medicine and 

 Surgery (P. Blakiston, Son, mid Co., Philadelphia, U.S.A.). 



This is a new Medical Journal, of which we have received 

 Nos. I and 2. Among the articles of interest is a valuable 

 continued paper on One Hundred Cases of Skin Diseases, by 

 Arthur Van HarHngen, M.D., in which the various treatments are 

 described. This Journal is addressed to the medical profession. 



Current IHoticea aub ffDemorant)a< 



The Sucking-Organs of Bees, Bugs, and Flies.— Dr. K. 



Kraepelin has described in the Zoologischer Anzeiger the mouth- 

 organs of the Bee and certain Hemiptera and Flies. In the 

 Humble-Bee the tube is composed of the labial palps and the 

 maxillae, which are connected with them by strips of chitinous 

 substance ; near their lower margin the paraglossse intervene 

 between the palps and the maxillae. The half-canal formed by the 

 upward curve of the margins of the labium gradually disappears 

 towards the posterior part of the latter, and allows liquid which 

 has passed down it to escape between the labium and maxillae 

 into the mouth, at the point of origin of the paraglossae. Besides 

 the tactile hairs, certain peculiar clavate pale hairs are placed on 

 the apex of the labium, which appear, from observations, to be 

 analogous to the olfactory hairs of the inner pair of antennae of 

 Crustacea, and, as they carry a minute opening at their ends, must 

 be considered as either gustatory or olfactory organs. 



Like that of Butterflies, the sucking-tube of the Hemiptera is 

 made up exclusively of the two maxillae, which unite in such a 

 way as to form a double cylinder, the upper division of which 

 carries the food, the lower the salivary secretion. The mandibles 

 lie by the side of the maxillae, and can move about on the tube. 

 The end of the labium is provided with terminal nervous organs. 

 In the proboscis of Diptera the sucking-tube is formed mainly by 

 the labium, which consists of a demi-canal, closed below partly by 

 the mandibles, which are connected with it by a groove-and-ridge 



