made in regard to the mandibles of (W/V,r will receive notice later, in the 

 description of those parts. 



Passing over a number of works, which dealt with the anatomy of single 

 species, or which had for their object the elucidation of the anatomy of special 

 organs, the next important discussion of the mouth-parts of diptera is by Menzbier. 



MENZBIKR,* in 1880, devotes the first twenty pages of his paper to a critical 

 historical synopsis of the works in which the mouth-parts of diptera have been 

 especially considered, and sixteen pages further to a critical historical summary 

 of the literature which treats of the development of the cliitin covering and 

 appendages of insects, and to the results of the studies of Weismann, Kunckel 

 d'Herculais. and others, upon the histoblasts, or imaginal disks. Succeeding the 

 historical part of his paper, Meuzbier details the results of his own investigations. 

 After enumerating the regions of the head, according to his ideas of its structure, 

 he explains (p. f)3-(>6) the mouth-parts of Haematopota, Si/rpkn.^ Empis, Mum-n 

 and Sargus, these genera representing a series, in which the first has all the 

 typical mouth-parts of a chewing insect, and the last only the labrum, labium, 

 and maxillary palpi. Menzbier seems to have been the first to recognize the 

 usual intimate union of the labrum and epipharynx in diptera, where he finds 

 them often separable by maceration in caustic potash. The following tabulation 

 gives, at a glance, the more important points in Menzbier's paper, in regard 

 to the mouth-parts of those diptera which he studied. 



