sept. i9io.] FUJIL -SOME REMARKS ON THE CRET. FLORA ETC. 215 



the past is warned. Grand'Eury and others admit the possi- 

 bility that the family in the remote past may have been able to 

 live under different conditions than those most favorable to 

 their living descendants. Nevertheless, it seems to me highly 

 probable that the majority of plants of the past, to see from 

 their internal behaviors and response towards external causes, 

 shown in their morphological, anatomical, and histological 

 structures, lived in the main under similar climatic conditions 

 as their allied members of the different groups of the present 

 day, if those members of the past showed a larger number of 

 characteristic habits and structures expressed by the present 

 members of the group and showed indications contradictory 

 to the latter. In case of our Cretaceous flora of Hokkai- 

 do (Yeso), it has been pointed out (Stopes and Fujir, 1910) 

 that 'the plants on the whole were those of a region which 

 was probably sub-tropical in its climate.' Hokkaido is at 

 present of a climate probably comparable to that of the main 

 part of Europe. Thus the climate seems to have changed from 

 the subtropic to the temperate. This change of temperature and 

 the consequent changes on the atmosphere and the substratum 

 seems to be an important factor worked upon so many plants 

 which are at present only known as fossils. From this point 

 of view a plant species capable of existence in a wider range of 

 climates, that is of latitudes and hights upon sea level, will 

 be one able to live for the longest under further changes of 

 temperature upon the earth in future. Naturally there are a 

 large number of conditions to be considered locally. 



Inherent characters on the part of individual plants too must 

 be naturally considered. As an example the diminutive capacity 

 of the pollination of Cycas revoluta may be mentioned. This 

 plant does not fruit well unless the ' sexes ' stand very near. 

 I have often experienced that they are incapable of pollination 

 when the two ' sexual ' individuals were apart only a hundred 

 meters or even less. It may due to the heavy weight, smaller 

 quantity or other conditions on the part of pollen grains or to 

 the primitive structure of the female flower, and certainly to the 

 condition of wind of the locality too. It is greatly contrasted 



