INDIVIDUAL SPECIES. 33 
respects, but that even plants obtained from seed sold under a 
similar name, if they have been produced in different countries, 
may differ in behaviour when grown in this country (12). 
At least four of these “varieties” have been used on the 
farm on which the present areas are situated, and it is very 
probable that these bought merely as “ Broad Red” or “ Red” 
Clover seeds may have had different countries of origin. 
Only on Areas 4 and 6 was a single variety sown, so that on 
the other areas it can not be determined which variety may have 
left persistent plants.’ This does not seem to be of very great 
importance here however, as the results obtained are all very low. 
Traces were recorded by the percentage frequency method 
on Area 2 at 64 and 74 years, on Area 3 at $4 years, and on 
Area 6 at 54 years, while on Area 6 also a P.c. fr. of o-1 was 
recorded at 44 years. The only other Pyc. fr. result was 0-4 per 
cent. on Area 4 at 134 years. 
The Specific Frequency results are more definite, although 
relatively few were obtained. After a seeding of ‘Broad Red” 
and “Cowgrass” a Sp. fr. of 19 was obtained on Area 1 at 34 
years, and a Sp. fr. of 1 at 44 years. With a heavier seeding, but 
of a similar kind, the plant was not recorded on Area 2 at <$ 
years, but it had sp. frequencies of 2 and 3 at 84 years and ro} 
years repectively, while a relatively light seeding of ‘ Broad 
Red ” and “ Hybrid Cow Clover” gave a Sp. fr. of 2 on Area 3 at 
7% years, and the same Sp. fr. was obtained on Area 5 at 104 
years with a heavy seeding of “Broad Red” and ‘ Cowgrass.” 
A Sp. fr. of 6 was found on Area 4 at 134 years. 
From these results it appears that under these conditions the 
development of the plant has two distinct periods. It decreases 
rapidly from sowing, so that at 44 or 5$ years it has practically if 
not quite disappeared. After this, itseems to increase slowly up 
to 134 years at least. 
It seems very probable that the second period of develop- 
1These ‘‘varieties” can not be separated by botanical characters fram 
each other, nor from the indigenous plants, in the vegetative state, 
