294 ALLAN KINGHORN — NOTES ON THE PRELIMINARY 



prouounced during the wave-like contractions of the body. When examined 

 under a pocket lens, the integument is seen to be very finely mammillated, and 

 these mammillae have a dark tint, which imparts the general appearance of 

 duskiness mentioned above. 



From the first segment two minute black bristles, about 0'5 mm. in length, 

 project. These are parallel to one another and are situated laterally on either 

 side of the middle line. On magnification they are seen to be club-shaped, and 

 are the representatives of the antennae. Between them lies the mouth, the lips 

 of which are directed doi'so-ventrally, and are blackish in colour. A trachea can 

 be traced, on either side, as a retractile tube extending from the base of the 

 tumid lips to about the central portion of the body, while on the mid-ventral line, 

 at the junction of the eleventh and twelfth segments, the anus is represented by 

 a small, round, black spot. 



The tumid lips are characterised by a row of short longitudinal striations along 

 the basal portion, from which spring two knob-like prominences, rounded exter- 

 nally, and separated by a comparatively deep sulcus. Internally they are 

 hollowed out to form a small cavity, on either side of which lies one of the 

 spiracles. The prominences are beset with small tubercles, and are marked off' 

 into three more or less equal portions by two shallow furrows. In colour the 

 tumid lips are jet-black. In his description of the pupa, Austen states that the 

 sulcus between the two knobs of the tumid lips does not show the key-hole shape 

 found in that of Glossina palpalis, but in many of our pupae, however, there is a 

 suggestion of such an outline, as will be noticed in fig 2, 



The behaviour of the larva differs somewhat with its surroundings. If left in 

 a glass dish it may crawl around for from one to two hours, but sooner or later, 

 becomes stationary, retracts its head, assumes the oval puparial form and proceeds 

 to pupate. The movements are worm-like, the contractions passing along the 

 body in waves. From time to time, the larva ceases to progress, and after re- 

 tracting the anterior end slightly, moves its head from side to side, and up and 

 down, as though trying to push aside some obstacle. The reason for this becomes 

 apparent as soon as it is placed on dry, powdered earth. In this situation the 

 larva at once commences to burrow down and is lost to sight in a minute or two. 

 When it has gone from one to two centimetres, it becomes quiet, and proceeds 

 to pupate as before. During this process the skin darkens gradually, and at the 

 same time hardens to form the pupa-case. These changes are usually completed 

 in from four to five hours. 



Apparently the larva is capable of secreting a slightly viscid fluid, for in glass 

 tubes they often adhere to the sides. When this has occurred, pupation soon 

 follows. The purpose of this fluid may perhaps be to gather the earth around 

 the pupa, and may possibly account for its not having been found earlier. 



The Puparium. 



In shape the puparium is more or less regularly ovoid, and varies in colour 

 from a dark reddish-brown to a dull matt brownish-black, contrasting with the 

 jet-black of the tumid lips. The pupa-case shows the mammillations mentioned 

 in the description of the larva. 



