DOMAIN OF EVOLUTIONARY HYPOTHESIS 121 



KEPTILES. 



Front of brain small, olfactory 

 centre well developed. 



One olfactory muscle. 



Neck immoveable ; one con- 

 dyle (swelling behind head). 



Oviparous ; eggs with shells 

 and with abundant yolk. 



MAMMALIA. 

 Front of brain large ; 



all 



Allantois (an embryonal for- 

 mation) is the urine bladder 

 and breathing organ. 



organs of sensation 

 higher sensitive centres in the 

 brain ; gradual progress in 

 intelligence (?). 



Three or more olfactory glands. 

 Neck moveable ; two condyles. 



Viviparous ; eggs with little 

 yolk or none. Ovum is con- 

 stantly nourished by maternal 

 secretions (uterine mucus, uter- 

 ine milk, blood serum and, later, 

 milk). 



Allantois is only the bladder 

 (many marsupials) or also the 

 bearer of the embryonal placental 

 vessels. 



Greater abundance of forms Greater abundance of forms 

 in the Permian formation and in the recent Tertiary formation, 

 until those of the Jura and the 

 Chalk. 



The orders in the class of the Mammalia are deter- 

 mined essentially on the basis of different construction 

 of the extremities and of the jaw. 



The plants are generally divided into five series 

 or families. This is done mainly according to the 

 degree of differentiation in the first place of the greater 

 groups of tissue the roots, stem, leaf and flower then 

 according to the greater or less perfect distribution 

 of work in the organ formation and the purposeful 



