224 VELD ESTIMATIOX. 



systematif lists were made, revealiiio- a dift'erenee of only three 

 species, which occurred in minute quantities. Hence a new 

 method had to he devised. I, therefore, sought to connf the 

 individuals of species present by taking- representative strips 

 or samples (" belt transects," Professor J. W. Bews has named 

 them) in eacdi ecologically different area in order to calculate 

 the proportion of every species present. Then, by reducing- to 

 percentag-es, the lists tor eacli paddock could be compared and 

 g-raphs drawn representing- the rang-e of variation. 



Typical belts, 10 feet by 150 feet (long-er or shorter as 

 necessary, and T- or L-shaped when required), were selected 

 and laid down permanently by pegging-. White twine was 

 stretched between the pegs, and the method of (-ounting- was 

 as follows : Each 10 feet square was estimated separately for 

 (a) the number of individuals, and (b) tlieir percentag-e, the 

 records being- entered on specially printed forms. It was 

 soon found that the unit 1 foot square (/.p., 1 per cent.) was 

 too large; and I divided the i)lot into four by cross bands of 

 twine, and the new unit, G inch square, was very convenient for 

 these closely g-rassed areas. 



The vertical shade area of the plants was taken in esti- 

 mating- tlieir percentage proportion. For g-rasses the G inch 

 square unit was again divided into five {\iz., 2^ inch square) 

 in order to estimate exactly the extremely variable sizes of 

 the tufts. Graphs were plotted only for the average of 10 feet 

 square plots. 



Remarkable results followed the appli(-ation of this 

 method, both in interest and importance. The results of 

 analysis of three belt transects frenn eac-h of the three paddocks 

 aforementioned, will be given in illustration, only the prin- 

 cipal plants being- selected, the averag-e pert-entag'es being' 

 cited : — 



Anthistiria imheihis: A G8-4 ; B 27-63; C 53-4. 

 Elionuru.^ argeutus : A 50; B 23-5G ; C T-24. 

 Eragrostis plana: A 0-5; B 4-57; C 4-91. 

 Eraqrostis chalcantha : A 2-0; B 7-4; C 5-8. 

 Sporoholu.^ indlcus: A 01; B 0-G3 ; C 0-2. 

 Harped,] oa capensis : X 0-G ; li 2-05; C 0-71. 

 Tristachya Jeucothri.r : A 1-5; B 3-23; C 1-94. 

 Paspalum .u-rohicuJafum : A 2-5; B 5-24; C 2-31. 

 A.ro7wpus seuiialatus : A 2-0; B 5-18; C 2-8. 

 I'anicinii scrratinn : A 0-5; li 3-92; (' ')-21. 

 Bidbostglis sp.: A 0-001; ]i 077; C 00013. 

 Vernonia 7iatalensix : A 1-50; B 0-18; C 105. 

 Acalypha depressincrc : A 1-5; B 2-91; C 214. 

 Aealypha Wilmsil : A 0-2 ; B 1-21; C 0317. 

 Pteridhnn aquiUnum : A 20; B 3-24; C 2-24. 

 Penfanisia ranahilis : A 1-5; 15 0-002; C 0-8G. 

 Watsonia densi flora: A 5-0; B 00025; (' 0135. 

 Vaagueria : A 0001 ; B 0-75 ; C 0-21. 

 Rlninchosia nerrosa : A 4'5 ; B 3'15; C 4-3. 



