S2 THE SUCCESSION OF ANIMAL FORMS 



I say survives ; for we have but a remnant of its forms living, 

 and comparatively little that is new has probably been added 

 since. The confusion which has obtained as to the age of 

 this flora, and its mistaken reference to the Miocene Tertiary, 

 have arisen in part from the fact that this modern flora was in 

 its earlier times contemporary with Cretaceous animals, and 

 survived the gradual change from the animal life of the Creta- 

 ceous down to that of the Eocene, and even of the Miocene. 

 In collections of these plants, from what may be termed beds 

 of transition from the Cretaceous to the Tertiary, we find many 

 plants of modern species, or so closely related that they may be 

 mere varietal forms. Some of these will be mentioned in the 

 next paper, and they show that modern plants, some of them 

 small and insignificant, others of gigantic size, reach back to a 

 time when the Mesozoic Dinosaurs were becoming extinct, and 

 the earliest Placental mammals being introduced. Shall we 

 say that these plants have propagated themselves unchanged 

 for half a milhon of years, or more ? ^ 



Take from the western Mesozoic a contrasting yet illustrative 

 fact. In the lowest Cretaceous rocks of Queen Charlotte's 

 Island, Mr. Richardson and Dr. G. M. r)awson find Ammon- 

 ites and allied Cephalopods similar in many respects to those 

 discovered farther south by the California Survey, and Mr. 

 Whiteaves finds that some of them are apparently not distinct 

 from species described by the Palaeontologists of the Geological 

 Survey of British India. On both sides of the Pacific these 

 shells lie entombed in solid rock, and the Pacific rolls between, 

 as of yore. Yet these species, genera, and even families are 

 all extinct — why, no man can tell, while land plants that must 

 have come in while the survivors of these Cephalopods still 

 lived, reach down to the present. How mysterious is all this, 



^ Among these are living species of ferns, one of them our common 

 "Sensitive Fern," of Eastern America, two species of Hazel still extant, 

 and Sequoias or giant pines, like those now surviving in California. 



