lOG GLOSSINA.— PALPI AND PROBOSCIS. 



of minute structural features, and a very detailed description 

 would scarcely be suitable for the present work.* 



A. External Mouth-parts in Glossina. 



I was unable to discover the slightest difference between 

 these parts in the male and female of Gl. palltdijpes, and the two 

 other species did not present any difference from the first-named 

 form worth mentioning. 



The maxillary palpi (Fig. 1, ^)t are somewhat longer than the 

 height of the head, horizontally projecting, with a deep longi- 

 tudinal groove on the side turned towards the plane of symmetry ; 

 they enclose the major part of the proboscis, of which only an 

 inflated basal portion (Z) is seen on the ujider side of the head. 

 The proboscis is rather thick at the base, but nearly three- 

 fourths of its length are proportionately exceedingly slender ; it 

 reaches almost to the end of the palpi, and is feebly curved, with 

 the concavity beneath. It consists of three parts (Fig. 2) ; the 

 upper Up or lahrum (a), the hypopliarynx (b), and the lower lip or 

 labium (c). 



* So far as I am aware, the mouth-parts of Glossina have never been 

 investigated before. Both Glossina and Sto7noxys are fairly near allies of 

 the European blow-flies (CallijyJwra erythroccpliala, Mg. and C. vomitoria, 

 L.), and the mouth-parts of Calliphora have been carefully studied by 

 K. Kraepelin {Zeitschr. f. ivissensch. Zool. 39 Bd. 1883, pp. 683-719, 

 Taf. XL.-XLI.) and B. T. Lovvne (" The Anatomy and Physiology of the 

 Blow-Fly." London, 1870) ; a second and greatly enlarged edition of 

 Lowne's work was published in 1890-95: "The Anatomy, Physiology, 

 Morphology, and Development of the Blow-Fly (Calliphora erythro- 

 cephala)." By B. T. Lowne. 2 Vols. (Loudon: E. H. Porter), 1890-95. 

 My description of the mouth-parts of Glossina and Stomoxys is not so 

 detailed as the accounts by Lowne and Kraepelin of those of Callipliora, 

 and I disagree with these authors as to some of their interpretations of 

 muscles, etc. ; but I have deemed it advisable to omit special references to 

 their statements as well as critical remarks on some of their opinions. 

 From earlier investigations I E^m well acquainted with the mouth-part? in 

 several families of Diptera (H. J. Hansen: "Fabrica Oris' Dipterorum, I. 

 (Tabanidse, Bombylidse, Asilidse, Thereva, Mydas, Apiocera) ; " Naturhist. 

 .Tidsskrift, 3. Baekke, B. 14, 1884, j)p, 1-220, Tab. I.-V.) ;— otherwise I 

 should not have ventured to examine notliiug but dried specimens of 

 Glossina. — I may add that F. Meinert, in his work entitled " Trophi 

 Dipterorum " (4to, KJ0benhavn, 1881), devotes two-thirds of a page and 

 three figures to the mouth-p,arts of Stomojx^s ; . this is,th,e only.jnodern 

 note on the proboscis in that genus. Meinert observes (p. 65) that the 

 labella of Stomoxys have "rows of teeth and chitinous blades," which form 

 " a saw with several rows of strong, sharp teeth, with which this Dipteron 

 is able to saw a hole in the skin of Mammals ; " but his drawing (Tab. V. 

 fig, 24) of the structure in question is very incomplete (the strong teeth 

 are wanting) and incorrect. 



t The references to figures in this Chapter all relate to Plates VIII. 

 and IX.— E. E. A. 



