564 CATALOGUES. 



likelihood of inadvertently omitting some. While writing ont a 

 long list of plant-names, the chance ia not small that one or 

 two may he left out, which ought to have been included. But 

 such an oversight introduces no other error into the list, 

 beyond the simple omission of some plant which might properly 

 have been given. Indeed, it is not an easy matter to make 

 sure of any local list being so absolutely complete that its 

 negative evidence can be quite relied upon. In some of our 

 printed Local Floras we find one or more species added like a 

 tail-piece at the end, either because first ascertained in the 

 county or other area while the Flora was under press, or 

 because accidentally left out of the manuscript as prepared for 

 the printing oflSce. 



The greater number of the cited Catalogues have been formed 

 in a different manner, one by which the chance of bringing in a 

 wrong plant is increased, while the chance of leaving out a 

 right one may be rather lessened. A printed list or general 

 catalogue of British Plants has been converted into a local 

 catalogue ; so managed by attaching some sign or mark to the 

 names of all those plants which have been observed by the 

 marker within some definite area. This mode is less likely to 

 induce errors of omission, perhaps, because the printed names 

 are there to serve as reminders. But, unless deliberate care be 

 taken in attaching the marks to the plant-names, there is the 

 risk of attaching some of them inadvertently to the wrong 

 names ; the hand and the thought not acting synchronaUy. 

 Such printed lists ought not only to be marked deliberately, but 

 to be also carefully read over after being marked. Eepeatedly, 

 before and while citing the Catalogues, it was found necessary 

 to re-apply to the marker, to ascertain whether he had really 

 intended to affix a mark to some particular plant suspected to 

 have been wrongly marked by him. 



After some experience had been acquired by noting the very 

 different manner in which local botanists looked at plants, — 

 more especially as to the likelihood of certain species being 



