QUADRATS 163 



gation of invasion year by year, and especially for succession, the method 

 of permanent quadrats is imperative, and the denuded quadrat an invaluable 

 aid. Changes, which would otherwise be incompletely observed and im- 

 perfectly recorded, are followed in the minutest detail and recorded with 

 perfect accuracy. 



20D. Possible objections. The use of the quadrat has led to the criticism 

 that it is needlessly detailed and thorough, and that, after all, the space 

 covered is but a minute part of the entire formation. The first objection is 

 one that has also been urged against the use of instruments of precision in 

 the habitat. It is always brought forward by those who have not used in- 

 struments, and as witnesses they are of necessity incompetent. No one who 

 is familiar with the instrument or the quadrat by actual practice has felt 

 that the methods based upon them were too thorough. In no case has the 

 writer ever listed or mapped a quadrat without discovering some new fact 

 or relation, or clearing up an old question. It can not be denied that quadrat 

 methods require both time and patience, but this is true of any kind of re- 

 search work. that is at all worth while. Every ecologist, moreover, that 

 has the interests of his field at heart and deprecates the present slipshod 

 work, will appreciate the necessity of methods which seem like drudgery 

 to the mere dabbler. 



The second objection, that the quadrat is at best but a small bit of the 

 area under investigation, seems at first to be a valid one. It can not be 

 gainsaid that the actual space studied is insignificant as compared with the 

 whole formation ; still, it must be obvious that even a single quadrat can 

 add at least some facts of value, which can never be obtained by the 

 best of general methods. Furthermore, if the formation be an actual 

 and not an imaginary one, a single quadrat will be in some measure repre- 

 sentative. In the more homogeneous ones, it will have much the same 

 value that a type specimen bears to the species established upon it. In 

 formations which are less uniform, its value is correspondingly reduced, so 

 that in formations which show marked zones, consocies, or patches, it 

 becomes n<:cessary to locate a quadrat in each. In the matter of representa- 

 tion alone, the graphic method of the quadrat map with its close-focus detail 

 photograph, is far superior to anything that can be obtained by the ordinary 

 description and photograph. Finally, the scientific study and recording 

 of succession, and particularly of competition, is an impossibility without 

 the aid of the permanent and denuded quadrat. The stoutest champion of 

 the practice of w^alking through a formation, and jotting down impressions, 

 can not avoid their use if he would attack these problems, and, once familiar 

 with the quadrat, his objections to the drudgery of thoroughness 'will 

 soon vanish. 



