xiv INVERTEBEATA 



CHAPTER XI 



POLYZOA 



The development of Membranipora as type of the Polyzoa ectoprocta The Cypho 

 nantes larva and its metamorphosis Other types of larvae belonging to the 

 Polyzoa ectoprocta The formation of buds in Polyzoa ectoprocta The develop- 

 ment of Pedicellina echinata as a type of the Polyzoa entoprocta : its larva and its 

 peculiar metamorphosis Ectoproct and Entoproct larvae compared General con- 

 clusion as to the ancestral history of Polyzoa, Ectoprocta, and Entoprocta. Page 386 



CHAPTER XII 

 BRACHIOPODA 



The development of Terebratulina septentrionalis as type of the Brachiopoda 

 Affinities of the Brachiopoda as indicated by their development . Page 407 



CHAPTER XIII 



ROTIFERA 



The development of Callidina russeola as a type of the Rotifera The affinities of the 

 Rotifera ......... Page 418 



CHAPTER XIV 

 CHAETOGNATHA 



The development of Sagitta bipunctata as a type of the Chaetognatha The ancestry 

 of the generative organs The affinities of the Chaetognatha . . Page 428 



CHAPTER XV 



NEMATODA 



The development of Ascaris megalocephala as a type of the Nematoda Methods of 

 obtaining, rearing, and preserving the eggs The cell-lineage The diminution 

 of chromatin The formation of layers The Rhabditis larva The development 

 of T-giants and the conclusions as to the constitution of the egg-cytoplasm to be 

 deduced from them The development of doubly-fertilized eggs and their bearing 

 on the causes of diminution of the chromation Experiments on the egg of 

 Ascaris The affinities of the Nematoda . . . . . Page 437 



CHAPTER XVI 



ECHINODERMATA 



The development of Asterias as a type of the Asteroidea Methods of obtaining the 

 eggs of Asterias Methods of preserving and mounting the eggs and larvae of 



