86 THE DRY-FLY MAN'S HANDBOOK 



identifying the insects on the water. The first of the 

 duns to hatch out is generally the dark olive, followed 

 by the olive duns, and the various patterns in the new 

 set, Nos. 7, 8, 9 and 10, are recommended during 

 the early and middle part of the month. Nos. 7 and 

 9 are the males, and 8 and 10 the females respectively 

 of the olive and dark olive duns. 



The expression hatch must be clearly understood 

 to refer to the first appearance in the winged stage, 

 although, of course, the true meaning of the word is 

 the emergence of the larva or nympha from the egg. 

 The word has been used in this anomalous sense for 

 so many generations by anglers that I think it well 

 to continue to use it notwithstanding the knowledge 

 that it is not scientifically accurate. 



The males of the majority of water-bred insects — and 

 especially in the case of the Ephemeridse — assume the 

 winged condition first and largely outnumber the 

 females. The males are slightly smaller and distinctly 

 darker in colour than the females, and in the genus 

 BaHis, which includes the olive and iron-blue duns, any 

 doubt as to sex can be quickly dispelled. A casual 

 examination with the naked eye will reveal the pre- 

 sence in the case of the males of a red-brown turban- 

 shaped cap on the top of the head which is absent 

 in the females. I have called this a cap from its 

 outward appearance, but as shown in Part H, "The 

 Fisherman's Entomology," it consists of two ex- 

 crescences side by side on the top of the head, which 

 are covered with facets, and are in fact compound eyes. 



