FLY. 



29 



Similarly, in the wonderfully beautiful and complex 

 proboscis of the hive bee there is, between each of tlie 

 trachea-like ducts, a row of minute pits (Fig. 29, Gs), 

 with a central papilla, which have been described by 

 Leydig, Meinert, Lowne, Kraepelin, and others, and 

 are probably organs of taste. 



Kraepelin * distinguishes four kinds of hairs on the 

 proboscis of the fly : 



1. Ordinary hairs, which are not hollow, and do not 

 stand in connection with a nerve. 



2. Hairs of touch. These are 

 principally situated on the upper 

 side. They are delicate, hollow, 

 pointed organs, situated on a ring 

 of the integument, and connected 

 with a nerve. 



3. Glandular hairs. These are 

 larger than the former, and the 

 chitinous ring is sometimes so much 

 developed as to form a short cylin- 

 der surrounding the base of the 

 hair. The principal characteristic 

 is, however, that the hair presents 

 along one surface a deep furrow, 

 and is connected at the base with a cellular organ. 

 Kraepelin therefore considers that this is a gland, and 

 that the secretion passes outwards along the furrow. 

 Kunckel and Gazagnaire, however, regard these also as 

 sense-hairs. The supposed gland they consider to be 

 a ganglion. 



4. Taste-organs (Fig. 30). These lie in a row between 



* Kraepelin, " Zur Anat. und Phys. dea Kussels von Musoa,'' Zeit. 

 fur Wiss. Zool, 1883. 



Fig. 29.— Tip of the probos- 

 cis in tlie hive bee (Apis), 

 X 140. Z., Terminal 

 ladle J Os, taste-hairs ; 

 Sh, guard-hairs ; Ifby 

 hoolced hairs. 



