CONTENTS OF VOL. III. 



The lung-sacs 



The intestinal canal . 



The mesodermal derivatives 



Blood-vascular system and coelom 



The coxal glands 



The genital organs . 



Chapteb XXI. ARACHNIDA. By E. Korschelt 

 I. Scorpiones .... 



1. Cleavage aud formation of the germ-layer 



2. The origin of the embryonic membranes and the development 



of the external form of the body . 



3. The formation of the organs 



A. The nervous system and the eyes 

 B. 

 C. 

 D. 

 E. 

 F. 

 G. 

 II. Pedipalpi 



III. Pseudoscorpiones .... 



IV. Opiliones 

 V. Solifugae 



VI. Araneae ..... 



Oviposition and constitution of the egg 



1. Cleavage and formation of germ-layers 



2. Development of the external form of the body 



3. The development of the organs 



A. The nervous system . 



B. The eyes .... 



C. Survey of the Arachnidan eyes 



D. The respiratory organs 



E. The spinning glands and the poison glands 



F. The intestinal canal and its appendages . 



The mesodermal structures . 



G. The blood-vascular system and the body-cavity 

 H, The coxal glands 



/. The genital organs 

 VII. Acarina ..... 



Oviposition ..... 



1. Embryonic development 



2. The formation of the larval integuments and the further 



course of development 

 VIII. General considerations regarding the Arachlrida 

 Literature .... 



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3d^f, 



