page 351 note * “Thus of 1,400 flies bred from pupae obtained on Damba Island the proportions were ♂ : ♀ :: 48 : 52. Whereas of 5,000 flies caught during the period in which the pupae were collected the proportions were ♂ : ♀ :: 78·6 : 21·4. ” Carpenter : Repts. of the S.S.Comm. of the Royal Soc., xii, p. 105.

page 355 note * These figures, apparently, represent about the daily emergence of males from pupae ; all the old flies of this sex appear to have been caught off.

page 356 note * By “density” is meant the number of flies which can be caught per boy per hour.

page 359 note * Proper attention to the following suggestions will serve to eliminate various possibilities of error :— (1) Boys should be trained at least one month; all new boys in a corps without one or or two experts as teachers would require longer training. (2) Nets must have a standard-sized ring and a standard length of handle; an 8-inch ring and 18-inch handle were used. (3) Catches should not be made before 8.30 or 9 a.m. nor later than 2.30 or 3 p.m. (4) Boys will make more even catches if provided each with a dark-coloured umbrella, upon which the files will settle, and from which they are easily caught. (5) Unless density is very low—less than 1·0—it is better not to spend more than 2 to 3 “boy hours” at the same point’ on the same day; density is easily reduced, temporarily, by catching. (6) Boys should be stationed along the routes most likely to be followed by moving files, and always, if there is shadow, at the edge of it. (7) Estimates of density must be based on catch of males, on account of the variability of female activity. (8) Good results cannot be secured on cool, cloudy or windy days.

page 369 note * These reasons include the following :— 1st. Because the females in any district or region appear to outnumber the males (see Sect. I (d) ). 2nd. Because the females must nourish their young as well as themselves, and most probably require food somewhat more frequently, in nature, than males. 3rd. Because the males are normally active at all times during good weather, and are more apt than the females to encounter host animals without specifically seeking for them.

page 382 note * Except on the sudd-surrounded islands of Baujako and Binga, where bush-buck, bush-pig and buffalo occur, and which are faunistically a parts of the mainland.

page 388 note * If the stream is so small that no break is caused in the continuity of the forest, fly has not been observed to follow it.

page 404 note * See also notes on “following swarm” Sect. IV.

page 406 note * The bite of G. palpalis may be absolutely painless, or it may be almost stinglike in sharpness, or anywhere between.

page 407 note * It is a curious trait of Glossina morsitans, and probably also of palpalis, to feed in confinement when they would not if unrestrained. Freshly captured, caged flies will usually feed promptly on the body of an animal pressed against the wire screen, when they would most certainly not have fed if uncaught.

page 409 note * In this case there was but one fly and it is not certain that it was attracted to the antelope.

page 415 note * It is possibly significant that the most favoured breeding places of the tsetse and of its prinicipal host, the crocodile, are virtually idential. Much the largest deposits of puparia have been found within a few yards of crocodile nests, in the same type of soil, and under the same type of vegetation that serves partially to shade the female crocodile as she “broods” above her egg deposit.

An almost equally striking correlation between breeding places of tsetse in vegetable depris and basking spots of Varanus, coupled with the finding of large deposits of puparia in the sunning spots of situtunga, suggests that the specific or characteristic preferences displayed by the flies for these hosts originated in the circumstance that flies feeding on them were most likely to propagate (instead of the converse: that flies propagating on send beaches or dry vegetable depris would therefore be most likely to feed on animals inhabiting the same localities.)

It is, indeed, most probable that the preference for certain hosts and for certain types of breeding grounds, now developed into specific characteristics, originated coincidentally, and together served to segregate Glossina palpalis from its congeners.

page 417 note * It is perhaps worth noting that both crocodile and Varanus like best to bask, not in the full sun, but with a part of the body shaded. The reason was learned through use of tethered Varanus in feeding experiments. It was found that an hour or two of exposure to the full effects of the sun would kill the cold-blooded reptile—more quickly by far than similar exposure would kill a warm-blooded animal. Varanus at least (and probably crocodile) is more susceptible to “sun-stroke” than man.

page 436 note * The very active and very sensitive host is as much an enemy of the flies as any parasite or predatory destructor known. There are many parasites and predators which would destroy the flies if they did not employ self-protective tactics against them ; there are several species of host animals which would do the same if the flies were devoid of self-protective instincts. The flies are actually exterminated by neither because of specialised instincts of self-preservation.

page 437 note * So alert, quick and sensitive a host as man must be approached by insect parasites with considerable circumspection ; the successful insect parasites of man appear either to approach him while asleep, as in the case of the bed-bug, the floor maggot, most mosquitos, etc., or to be extraordinarily insidious, like the chigger, or to be exceptionally resistent to retaliatory activities like fleas, and some others.

page 451 note * The females nourish the young larva until it is full fed and ready to transform into the pupa, equal in size to herself. Normally she must feed (engorge) at least 3, probably 4 and possibly 5 times in order to provide sufficient food for a single larva.