Life- History. 



17 



extracted from the dead bodies of the females, this 

 pedicel may not always belong to the egg proper, 

 especiall}- as that of ^\ striolatuin (No. 2), which was 

 laid naturalh', has not got it. The eggs themselves are 

 smooth and nearh' colourless, but have just a \'ellow 

 tint. The contents are granular, and, no doubt, consist 

 to a great extent of protoplasm, with possibly some 

 oil}' globules. At an\- rate, their appearance gives 

 one that impression. Though so small fand the largest, 

 that of ^{nax iiiipcratoi\ of which No. 5 (Fig. 4) is an 

 illustration, is but i^mm.* in length), Dragonflies' e<7cs 

 have parasites we are told. A tiny h}-menopterous insect, 

 of the family JMyniaridcc, passes its early stages in them. 

 Mr. F. Fnock, who makes a study of these minute 



creatures, says that he 

 has bred from Dragonflies' 

 eggs many specimens, both 

 male and female, of Ana- 

 griis iitcaiiiatits, one of 

 these minute Mymarids 

 less than 4-iTim. in length. 

 These Fairy-flies, as they 

 are called in the \ulgar 

 tongue, when they leave 

 the Dragonfly's eggs as 

 perfect insects, use their 

 curious wings to swim to 

 the surface of the water, where, owing to their micro- 

 scopic size, it is difficult to find them (Fig. 5). 



Fk;. 5. — Anagkis inxarxatu: 



(After F. Knock.) 



Parasitic in Eggs of Dragonfly, 



(Greatly magnified.) 



* It has seemed well in most cases to make the millimetre the unit of 

 length, not only because its value is u^Jer^tood in all civilised countries, 

 but because many measurements we have to make are so small that an 

 inch becomes unwieldy. For practical purposes 25mm.= iin. 



C 



