27 



band of longitudinal ridges, and the outer surface of each lip or pro- 

 tuberance is, as usual, granular (though the granulations are not nearly 

 so coarse or sharply denned as in the case of G. palpalis), and bears 

 two more or less clearly marked grooves or furrows, which thus divide 

 it into three prominences. The lips are actually smaller than in 

 G. palpalis and different in shape (not so full and rounded). A dried 

 larva of G. brevipalpis from Amani (Dr. F. Vosseler), measuring 

 9-5 in length, by 4 -25 mm. in greatest width, shows that the inner 

 surfaces of the tumid lips, instead of being close together and separated 

 by a deep and narrow notch, as in G. palpalis, are divided by a relatively 

 wide and shallow space, something like a wide V." 



PUPATION. In his " Notes on the Preliminary Stages of Glossina 

 morsitans, Westw.," from which we have already quoted, Dr. Kinghorn 

 (79) writes : " 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 move- 

 ments are worm-like, the contractions passing along the body in waves. 

 From time to time the larva ceases to progress, and after retracting 

 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/' 



A different explanation of the function of the fluid in question was, 

 however, subsequently given by Lamborn (83). In an account of 

 observations on the larva of G. morsitans, made by him in Nyasaland, 

 this author says : " As has been already noted by previous observers, 

 the newly born larva is covered with a clear slimy secretion, and a 

 theory has been advanced that the purpose of this is to cause earth 

 to adhere so that the pupae are less readily recognised by scratching 

 animals. This supposition has not seemed to me to be tenable, seeing 

 that one never finds such a covering, however carefully one digs up 

 the pupae ; and, moreover, though a certain amount of dust does cling 

 to the pupa, it is invariably in the form of minute particles only in the 

 neighbourhood of the intersegmental rings. 



" A more likely supposition has seemed to me that the secretion might 

 have a protective function, the period between the birth of the larva 

 and its burying itself in the ground, during which it crawls on the 

 surface, being probably the most critical in the life-history of the fly. 

 Ants are invariably found in the breeding places, and as they depend 

 so largely on insect food, a series of experiments have been conducted 

 with a view to finding out the attitude of various species towards the 

 larvae." After describing the behaviour of three different species of 

 ants when confronted with Glossina larvae, Dr. Lamborn writes : 

 " From these results I think that a reasonable inference mav be drawn 



