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ence is, and the more the power of observation is 

 cultivated, the more complex does the question become- 

 The more keenly one studies the accepted species in any 

 one genus, the more one realises that the division into 

 species is a man-made convention. Increased study shows 

 that plants are so affected by altitude, soil, situation, and 

 a host of other factors, that apparently innumerable inter- 

 mediate forms connect two closely allied species. Perhaps, 

 too, hybrids occur, which still further puzzle the student. 



Every fern student can at once distinguish the main 

 species or varieties by "some peculiarity which arrests the 

 eye, but which he has been unable to describe." But 

 everyone will also agree with Dr. Stansfield that this is 

 unsatisfactory. Some forms or varieties are unstable, 

 varying from season to season. Others seem much more 

 permanent, and vary very considerably from the type, and 

 yet these are often put aside by the botanist as un- 

 important. Is the presence of intermediate forms between 

 two distinct types considered as proof that one is only a 

 variety of the other ? Take an example of a fern genus in 

 which intermediate forms are common. Lastrea dilatata is 

 generally taken to be a variety of L. spimtlosa. So is 

 L. aemula. In the ordinary way these appear, to one with 

 no more experience than. I have, as being distinct enough 

 to be classed as species. Dr. Stansfield gives a host of 

 distinguishing characters for each, which one thought 

 would have entitled it to specific rank. Each has its own 

 character with regard to rootstock, arrangement of un- 

 developed fronds, stipes, scales, character of frond, and 

 habitat. Surely the botanical world can supply examples 

 of accepted species separated by no more important or 

 permanent characters than the above ? 



In this connection, it was interesting to look up what 

 the two or three text books immediately available had to 

 say. The well-known " Hooker and Bentham " is notedly 



