THE ANOPHELINA SUB-FAMILY 285 



" insects' drowsy hum " of the popular lyricist, while the rapidly 

 vibrating wings of the smaller fry cannot but make a "shrill 

 pipe." That we hear more of this in the case of Mosquitoes 

 than in most other smaller insects, is due to the fact that the 

 affection they entertain for us leads them to hover close to our 

 ears preparatory to imprinting the tokens of their regard that we 

 have such strong reasons for avoiding ; reasons which render us 

 particularly alert to the sound. 



Personally, I am inclined to think that the bite of Anopheles 

 is neither more nor less irritating than that of other Mosquitoes, 

 and that the differences of opinion on this point are due to the 

 varying degree of immunity which all, more or less, acquire ; and 

 also to the circumstance that any specially virulent effects are 

 usually due, not to the venom of the Mosquito itself, but to 

 accidental impurities introduced along with it, 



I have again and again seen middle-aged Indians, who had 

 long lost all power of reacting to the pure salivary secretion 

 of Mosquitoes, actually apply for treatment an account of their 

 faces being so swollen that they could scarcely open their eyes, 

 and the fact that such cases are specially apt to occur among 

 patients lying in a surgical ward makes it probable that the 

 unusual effect of the bites is in such cases due to the Mosquitoes 

 having indulged in a previous feed from some wound secretion. 

 Occasionally the swelling in such cases has an erysipelatous 

 character, and I have met with suppuration ; but as a rule, it 

 subsides in a day or two. 



In the same way, it may be doubted if it is safe to generalise 

 on the supposed preference of Mosquitoes for the blood of any 

 particular variety of the human race. 



That they should be able to follow up the trail of an adult 

 "buck nigger" more readily than that of the well-groomed 

 European can be easily understood, without assuming that 

 Mosquitoes find Kru-boy tastes nicer than Englishman ; and in 

 India, where the personal habits of the indigenous population are 

 more cleanly than those of the West African, one hears nothing 

 of such preference. In any case, however, the number of 

 Mosquitoes of any given species may vary so greatly on conse- 

 cutive days of the same week, owing probably to differences in 

 the state of the atmosphere, that something more than a few 

 desultory observations are required to justify the expression of 

 any opinion on the point. 



The identification of the various species in this genus is 

 rendered none the easier by the fact that most of the most 



