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A BEAUTIFUL FERN GROUP. 



We are indebted to the kindness of the Rev. Canon 

 Kingsmill Moore for the loan of a block illustrating his 

 exhibit in Dublin last year of six British Ferns. As these 

 speak for themselves, we need but to indicate their names. 

 From left to right, back row, stand P. acul. pulcherrimum 

 (Beavis), the parent of the gracillimum section, A. f.f. 

 formoso cristatum, and A. f.f. cvistcitum densum (which seems 

 to be hardly well named), and in front P. ang. plutnosum- 

 loxum (Jones and Fox), P. acul. gracillimum Dvuevyii 

 (young plant), and P. ang. plumostim Esplan. These 

 deservedly gained the first prize, all being not only of the 

 elite, but capitally grown. 



THE CAUSE OF VARIATION. 



One of the most burning questions of the day in biolo- 

 gical circles is that relating to the reason why plants 

 which have presumably adhered for long periods to 

 structural and other characters peculiar to their species, 

 transmitting these practically truly for many generations, 

 should apparently suddenly abandon these to a greater or 

 less extent and adopt others of, it may be, a widely different 

 character. This adoption it is found is, as a rule, of a 

 permanent character, the new " characters" being trans- 

 mitted to the offspring by seed or spore, so that to all 

 intents and purposes a new species comes into existence. 

 The botanist, however, recognizing the retention of some 

 of the old specific characters, which may be termed 

 fundamental ones, such as those connected with the mode 

 of reproduction peculiar to the genus of the plants con- 

 cerned, and also, as a rule, some of the merely specific 

 ones in a modified form, refuses to accept these " sports " 

 or " mutations," as they are termed, as true species, 

 regarding them as mere "varieties." For a very long 



