706 



APPENDIX. 



not assuming their strange forms. From the non-segmented, 



sac-like larva it passes directly into the pupa state. 



The development of Teleas is like that of Platygaster. 



Fig. 656 A, represents the egg ; B, (7, and D, the first stage 

 Fig. 656. of the larva, the ab- 



domen (or posterior 

 division of the bod}^) 

 being furnished with 

 a series of bristles 

 on each side. B 

 represents the ven- 

 tral, C the dorsal, 

 and D the profile 

 view ; ctf, antennae ; 

 md, hook-like man- 

 dibles ; mo, mouth ; 

 &, bristles ; m, intes- 

 tine ; sw, the tail, 

 and ul, under lip, or 

 labium. In the sec 

 end larval stage, 



which is oval in form, and non-segmented, the primitive band 



is formed. 



Development of Egg-parasites. 



The Embryonal, Membranes of Insects. — After the forma- 

 tion of the germinal layer or blastoderm, the outer layer of 

 blastodermic cells peels off or moults, forming the so-called "am- 

 nion" ("parietal membrane" of Brandt, Fig. 657, am). This 

 skin is a moult from the blastoderm. At a later period, after 

 the formation of the primitive band, a second membrane (Fig. 

 657, db "faltenblatt" of Weismann ; visceral la3"er of Brandt) 

 separates from the primitive band. It surrounds the embr^'o 

 in the Hymenoptera, Diptera and Coleoptera, enveloping the 

 limbs, and is shed as a thin pellicle when the embryo leaves 

 the &gg. Melnikow (Archiv fiir Naturgeschichte, 1869, p. 136) 

 from whose article the accompanying figure is taken, shows 

 that in the lice, however, both the amnion and visceral mem- 

 brane share in building up the body of the embryo, and pass 

 upon the dorsal side of the embryo. Brandt (Memoirs of the 



