ON ZYGODON IIUPESTBIS. 205 



rupestris, or are these characters not of sufficient importance, consider- 

 ing certain intermediate forms, to cause it to rank higher than a 

 variety ? Of course the decision will rest very much upon our ideas 

 of what a species is. From a Darwinian point of view, I think we 

 should call it at the least an incipient species, altered somewhat perhaps 

 from a change of habitat or environment. Then, again, the excurrence 

 or otherwise of a nerve is considered of some value as a specific dis- 

 tinction in many cases, and in this particular one, where all the other 

 British species of the genus have a nerve vanishing below the apex, it 

 should have a higher value. Then, again, the shape of the leaf is not 

 the same ; while viridissimus has a leaf which from its widest 

 portion — nearer the base than the middle — gradually and regularly 

 tapers upwards to an acute apex, that of rupestris is very nearly the 

 same width throughout its whole length, or at any rate is only very 

 slightly narrower at the point where it suddenly bends towards the 

 nerve. The name viridissimus itself indicates the intense green 

 colour of the fresh plant found on trees, whereas the rock specimens are 

 almost always more or less of a brownish-green colour ; and though this 

 may possibly be owing to the difference in their habitat, yet still the 

 name viridissimus is certainly inapplicable to a species which includes 

 a variety of so different a hue ; but this is only of minor importance. 

 There are one or two foreign species which possess an excurrent nerve, 

 as Z. anomalus, Dz. et Molkb., and Z. Schimperi, Hmp. ; in the latter 

 it is very similar to our plants, viz., '•'■ nervo excur recite ferrugineo,''^ 

 according to Mueller. 



I have been led to make these few remarks with the hope of calling 

 the attention of much more competent bryologists than myself to this 

 rock form, which I think has perhaps been somewhat hastily referred 

 to viridissimus as a variety, and of ascertaining from them whether 

 these characters, combined with its habitat, are not sufficient to raise it 

 to the rank of a species. On comparing the characters on which 

 many other species are based, I think it will stand a fair comparison 

 with many of them, as for instance, the slight difference between 

 Bryum sanguineum and B. murale. 



In conclusion, I beg to thank those gentlemen who have so readily 

 favoured me with specimens for their great kindness in so doing, viz., 

 Messrs. J. Gr. Baker, S. A. Stewart, Dr. Trimen, and the Rev. J 

 Fergusson, 



Huddersjield, July 10, 1875. 



P.S. — Since writing the above I have received the 2nd edition of 

 Schimper's Synop. Muse. Europ., 1876, in which I am somewhat sur- 

 prised to find that no mention is made of this form, either as a species 

 or a variety. 



NOTES ON SOME CHINESE PLANTS, WITH DESCRIPTIONS 



OF A FEW NEW SPECIES. 



By W. B. Hemsley, A.L.S. 



So little is known respecting the botany of the interior of China, and 

 80 much yet remains to be done in the investigation of the vegetation of 

 themorefullyexploredcoastregion, that almost every collection of plants 



