SPECIES AS TO VARIATION, ETC. 197 



throughout, a larger number — through the operation 

 of some deep-seated and innate principle, which we 

 cannot fathom — change abruptly into the other species 

 at the second or third node, and change back again in 

 the flower, or else effect a synthesis of the two species 

 in a manner which is puzzling to understand. Here 

 is a change from one fixed law to another, as unac- 

 countable, if not as great, as from one specific form 

 to another. 



An elaborate paper on the vegetation of the Ter- 

 tiary period in the southeast of France, by Count Gas- 

 ton de Saporta, published in the Annales des Sciences 

 NaturelUs in 1862, vol. xvi., pp. 309-311 — which we 

 have not space to analyze — is worthy of attention from 

 the general inquirer, on account of its analysis of the 

 Tertiary flora into its separate types, Cretaceous, Aus- 

 tral, Tropical, and Boreal, each of which has its separate 

 and different history — and for the announcement that 

 " the hiatus, which, in the idea of most geologists, 

 intervened between the close of the Cretaceous and 

 the beginning of the Tertiary, appears to have had no 

 existence, so far as concerns the vegetation; that in 

 general it was not by means of a total overthrow, fol- 

 lowed by a complete new emission of species, that the 

 flora has been renewed at each successive period ; and 

 that while the plants of Southern Europe inherited 

 from the Cretaceous period more or less rapidly dis- 

 appeared, as also the austral forms, and later the trop- 

 ical types (except the laurel, the myrtle, and the 

 Ohamcej'ops humilis\ the boreal types, coming later, 

 survived all the others, and now compose, either in 

 Europe, or in the north of Asia, or in North America, 



