126 AMERICAN JOURNAL 



1. The young are born in a helpless state (often blind) but the 

 parents are able to nurse and educate their progeny. Educabilia 

 (Bonap.), Mammalia ; Altrices,* Owen, among Birds. 



Among the lower animals nursing is probably replaced by 

 metamorphosis. The animals which are nursed with the greatest 

 care, or undergo the greatest number of phases in their develop- 

 ment, may be considered the highest in their respective classes, 

 e. g., Coleoptera among Mandibulata, Hymenoptera and Lepi- 

 doptera among Haustellata. 



Metamorphosis through a nurse may be considered as indica- 

 ting inferiority of the adult state. 



2. The young make their appearance in a state of adolescence 

 (freely moving) and need no metamorphosis to reach the mature 

 state. This kind of propagation may be considered a character 

 of inferiority. 



Expl. — Ineducabilia (Bonap.) among Mammalia, Prsecoces 

 (Owen) among Birds, Ametabola among Mandibulata and Haus- 

 tellata. 



Propagation by budding is a character of inferiority, e. g., 

 Aphides, Tunicata, Bryozoa, Acalepha. 



XI. The different kinds of food and the manner in which it is 

 seized and prepared aflbrd the principal characters limiting orders 

 and families. 



I. Manducahilia, which divide the food in morsels. 



1. Zoophaga, animals which have means of catching and kill- 

 ing other animals ; only few divisions are composed of species 

 living exclusively upon animal food. (Ursus, Zabrus.) 



2. Necrophaga ; feeding upon dead bodies is a character of 

 inferiority and indicates only the limits of families. Carnivora 

 are generally considered the highest in their respective divisions, 

 as it requires considerable skill in catching their prey ; yet the 

 frugivorous and insectivorus, Quadrumana and Scansores are con- 

 sidered superior to the carnivorous groups. 



3. Insectivora and Frugivora are very natural groups among 

 Quadrumana, Bats, Edentata, Scansores, &c. 



4. Phytophaga, feeding upon vegetable matter, chiefly leaves, 

 e.g., Ungulata, Lamellicornia, Helicea, which contains the largest 

 terrestrial forms. 



* Gymnogenous. Hestogenous of Newman (Proc. of the Zool. Soc, 

 1850, p. 46.) These divisions are not analogous to Placentalia and Apla- 

 centalia, which probably are not represented in birds, unless the habit of 

 Sthruthious birds depositing some eggs for food of the young, may be 

 considered an analogy of marsupialism. 



