BEES PROBOSCIS I 3 



structure exists in neither of the parents. It is, in fact, a case 

 of a very special adaptation appearing in the majority of the 

 individuals of each generation, though nothing of the sort occurs 

 in either parent. 



The proboscis of the bee l is a very complex organ, and in its 

 extremely developed forms exhibits a complication of details and 

 a delicacy of structure that elicit the admiration of all who study 

 it. In the lower bees, however, especially in Prosopis, it exists 

 in a comparatively simple form (Fig. 9, B, C), that differs but little 

 from what is seen in some Vespidae or Fossores. The upper lip 

 and the mandibles do not take any part in the formation of the 

 bee's proboscis, which is consequently entirely made up from the 

 lower lip and the maxillae, the former of these two organs ex- 

 hibiting the greatest modifications. The proboscis is situate on 

 the lower part of the head, and in repose is not visible ; a portion, 

 and that by no means an inconsiderable one, of its modifications 

 being for the purpose of its withdrawal and protection when not 

 in use. For this object the under side of the head is provided 

 with a very deep groove, in which the whole organ is, in bees 

 with a short proboscis, withdrawn ; in the Apidae with a long pro- 

 boscis this groove also exists, and the basal part of the proboscis 

 is buried in it during repose, while the other parts of the elon- 

 gate organ are doubled on the basal part, so that they extend 

 backwards under the body, and the front end or tip of the tongue 

 is, when in repose, its most posterior part. 



For the extrusion of the proboscis there exists a special 

 apparatus that comes into play after the mandibles are unlocked 

 and the labrum lifted. This extensive apparatus cannot be satis- 

 factorily illustrated by a drawing, as the parts composing it are 

 placed in different planes ; but it may be described by saying 

 that the cardo, or basal hinge of the maxilla, changes from an 

 oblique to a vertical position, and thrusts the base of the pro- 

 boscis out of the groove. The maxillae form the outer sheath of the 

 proboscis, the lower lip its medial part (see Figs. 7 and 9) ; the 

 base of the lower lip is attached to the submentum, which rises 

 with the cardo so that labium and maxillae are lifted together ; 

 the co-operation of these two parts is effected by an angular piece 

 called the lorum, in which the base of the submentum rests ; the 



1 In studying the proboscis the student will do well to take a Bombus as an 

 example ; its anatomy being more easily deciphered than that of the honey-bee. 



