CHAPTER I. 



THE LIFE-HISTORY OF THE BLOW-FLY. 



The life-history of the blow-fly may be conveniently divided 

 into four stages ; (i) the egg ; (2) the larva ; (3) the pupa, and 

 (4) the imago states. 



The Egg. — The female insect deposits her eggs in packets on 

 those parts of dead birds or animals which are not covered by 

 hair or feathers, or upon raw or even cooked meat ; and 

 occasionally, it is said, upon the fleshy petals of certain plants 

 (Stapelia, etc.) which have a carrion-hke smell. The number 

 of eggs in each packet varies between three or four and a 

 hundred or more. 



The eggs are usually fecundated at the moment of deposition, 

 and the larva effects its escape from the egg in from twenty to 

 twenty-four hours. 



At the end of the first twelve hours the embryo already 

 possesses a rudimentary head with all those parts usually 

 found in insects at a corresponding period of development. 



Bibliography.— In this and the following bibliographies it has not been 

 my intention to include every book upon the subject, but only those to 

 which I am indebted, or which possess historic interest and contain original 

 work. The numerals prefixed are given in the text thus [8], when a work is 

 quoted or referred to, and are consecutive. 



1. Reaumur, De, ' M^moires pour servir a I'Histoire des Insectes,' 4to., 



torn, iv., Paris, 1738. 



The fourth and seventh Mem. are in part devoted to the life- 

 history of the blow-fly, and are exceedingly interesting. 



2. Weismann, A., 'Entwicklung der Dipteren.' Leipzig, 1864. Also in 



Zeitsch. f. wissensch. Zool., Bd. xiii. and xiv. 1863-64. 



3. Gleichen, W. F. F., ' Geschichte der gemeinen Stubenfliege ' (The 



House-fly). Niirnberg, 1790. 



Is interesting on account of its antiquity, and gives an account of the 

 life-history of the house-fly. 



I 



