THE AMERICAN BOTANIST. 9 



one species of a single genus of a very large family. Its 

 freaks, queer enough to start with, are played upon in a hun- 

 dred dififerent ways till they become the dread even of the pro- 

 fessional. Take examples from the one multiform genus Eu- 

 phorbia. How could we ever imagine that the splendid Poin- 

 scttia with its long scarlet bracts, or the snake-like Euphorbia 

 of hothouses, or the very pretty "snow on the mountains" of 

 our Western States, or the little weedy ones suggesting purs- 

 lane, and growing between bricks in a pathway, were not only 

 of one family but one genus. While the recognition of a 

 P'lant as a spurge is not difficult, to relegate it to its proper po- 

 sition in a system, or still more to describe it, will test one's 

 utmost skill in taxonomy. One curious fact should be added, 

 namely, that in hot dry desert regions in the old world, they re- 

 place the Cacti of the New and imitate their concentrated 

 forms. 



Providence, R. I. 



Ferxs axd Lime. — It is often assumed that all ferns love 

 limestone and that certain species will not thrive unless in a soil 

 of this nature. This was once said of the walking fern and 

 it is still the custom to mix limestone, old plaster, etc., with 

 the soil in that part of the fern garden where these ferns are 

 to be placed. But since this idea became current the walking 

 tern has been found on a large number of rocks that contain 

 no trace of lime, and at present not a few believe that the 

 leason for the occurrence of some ferns on limestone is the 

 same as the reason for certain plants growing in alkaline soils 

 or in deserts, namely, that they cannot hold their own against 

 the tenants of other soils. Not only is this true that many 

 i'crns are not lovers of lime, but there are some species that 

 cannot endure it. Loniaria Spicant and Cryptograinina crispa 

 are reported as unable to survive if watered with water con- 

 taining much lime. — Fern Bulletin. 



