798' THE POPULAR SCIENCE MONTHLY. 



special conditions of every valley and hill-top. Yet the knowledge 

 and insight that determine the relative hardiness of plants seem easy 

 of acquisition in the eyes of the inexperienced. Still, no one, really an 

 expert in such matters, will venture to express a decided opinion on 

 such data as are usually obtainable. A canny Scot of our acquaintance, 

 whose knowledge of plants in a practical way is encyclopedic if such 

 a term in such a connection be admissible is a notable example of this 

 wise cautiousness. Never was he known to positively commit himself, 

 at least on the subject of the peculiarities of plants. " They might 

 be hardy," he would say, " and again they might not. Circumstances 

 alter cases." There was always a profound consideration shown for 

 the incalculable effects of any particular environment. 



That we may better realize the strangely complex character of the 

 relative hardiness of plants, let us consider briefly the special behavior 

 of various kinds under apparently similar conditions, and then note 

 with cai'e their behavior under evidently different conditions. Take 

 Japanese plants, for instance. They illustrate how, sometimes, on two 

 sides of the globe, in the same latitude, almost identical species and 

 varieties appear. Whether it is the similarity of the course of the 

 oceanic currents along their shores and the trend of the mountain- 

 ranges inland that modify the two climates into a peculiar likeness, or 

 still more recondite causes, the fact remains that whole genera of Jap- 

 anese plants resemble in the strangest way indigenous American kinds. 

 Retinosporas, the most popular evergreens of Japan, seem, in some 

 cases, though confessedly distinct botanically, nearly identical in ap- 

 pearance with Thujas or American arbor- vitaes, and they also behave 

 alike. In grafting, for instance, members of one genus require mem- 

 bers of the same genus as stocks. Yet the Retinosporas, which graft 

 well, of course, on their own stock, graft also with entire success on the 

 American arbor-vitte, which the botanist tells us is an entii'ely distinct 

 genus. They are, likewise, equally hardy, but the variation in form 

 and color, in both Japan and America, is much greater among Retino- 

 sporas than among American arboi'-vitoes. This capacity for endurance 

 of like conditions which appears among Japanese and Eastern Ameri- 

 can evergreens runs also through deciduous trees. There are maples 

 on the Amoor River and in Japan which have little to distinguish them 

 from at least one variety of maples in America, and there is a similar 

 kinship in reference to hardiness. 



These instances of resemblances in hardiness and in other features, 

 between plants botanically widely different, might be greatly multi- 

 plied, but those mentioned will suffice to show the widespread likeness, 

 in these respects, of many different plants throughout the globe. In 

 face of these extraordinary instances of similarity in hardiness of plants 

 the native haunts of which are widely removed, we have to recog- 

 nize the existence of many kinds in the same region, closely related 

 botanically, and yet entirely different in their several degrees of hardi- 



