INDIVIDUAL SPECIES. 25 
recorded on Area 6 at 54, 64 and 74 years in quantities up to 1-6 
per cent., but it seems to have been adversely affected by the 
heavy grazing with sheep and (or) drought in 1918.* 
Poa annua. 
This was generally of little or no importance, but it had the 
very high P.c. fr. of 8-4 on Area 1 at 4} years. Probably this 
was due to the open condition of the young pasture. 
Cynosurus cristatus. 
Armstrong (I) found this grass to be more abundant on 
inferior old pastures than on better pastures, but even in first-rate 
old pastures he foundits range to be from 4-4 to 11-3 per cent. 
of the total herbage. On the best pasture examined by the 
present writer it had a P.c. fr. of 12-9 at 18 years. It is not 
known whether it had been sown in this field or not. 
The grass is strongly indigenous to Areas 1-4, but exotic to 
Areas 6-8 under natural conditions. Its seed was not intentionally 
sown on the farm until 1911, but it was very prominent on 
Areas 1, 2 and 3 in the pastures which preceded that of the 
rotation under investigation. It was especially prominent in the 
hay crop taken from Area 2 in 1905. 
Its seed was not included in the seeds-mixtures for Areas 1-4, 
and since it very rarely occurs as an impurity in other seed samples 
(8), (x), (14), its occurrence on these areas must be considered 
as more or less natural. 
On Area 1 its development was very weak at 44 years, but it 
had increased considerably at 54 years. Even then, however, 
its P.c. fr. was much lower than on Area 2 at the corresponding 
period. On the latter area it had a P.c. fr. of 8-1 at 54 years, 
and with a small set back at 84, it increased regularly from year 
to year to 14-7 at ro$ years. By this time it had exceeded the 
P.c. fr. on Area 4 at 134 years, so that probably on that area there 
had been a slight decrease. On Area 3 it was considerably less 
well developed than on Area 2 at corresponding periods, and even 
showed a decrease from 84 years to 94 years. 
tcf Stapledon (15). 
