J.3U 



Cooperatlre lurestigations oii Plauts 



TABLE III. 

 Frequency of Petais jier 1000. 



Biit iiiakiiig all allowaiu'o for this thc (u-niian and Swiss sei'ies shciw a inai-kcd 

 increase in the number of both .sepals and petais over cur serie.s, culminating 

 in Gais witli its inodes of 5 sc^jials and 10 jx'tals. Oiir Dorsetshirc series indioatcs 

 a substantial advance in the sanie direction as far as the petais are conccrued, thc 

 ßordigheia tends somewhat in the same direction for thc petais. It reniains as a 

 task for next s])ring to detcrmine whother the Gucrnsey and Gais series cannot be 

 linked together by a continiious systeni of intermediatc .series, if only the flowers 

 bu gathered at a sufficicnLly wide ränge of places and at different seasons in those 

 places. 



(5) Turning to the correlations which involve sepals onc is hardly siirprised 

 at their irregularity, for their values dopend in onr new data ou thc distribiition of 

 a very few individual.s with more thaii fonr sepals. These for Bordiglu-ra are 

 less than 7 per cent., for Dorset less than 3 per cent., and for Guernsey and Surrey 

 not more than 1 per cent. ! Hence one or two irregulär or anomalotis individuals 

 cause the correlation to alter in a very remarkable niainier. A inucli safer sct 

 of correlations are those between petais, stamens and pistils. Unfortunately the 

 oounting of stamens and pistils is a much Härder task, and for a series of .^00 

 bud-gatherings rccjuires a weck or two of very laborious work. 



Looking at our new data, which ai"e arranged according to number of stamens, 

 we see several important and almost uniform results : 



(a) If the different series be an-anged in ascending order of stamens, this will 

 also be an a-scending order for the number of pistils. 



With one exception — Surrey — this is also an ascending order for the number 

 of petais. 



(b) The ascending order for stamens or pistils is also an ascending order 

 for the variability of both stamens and pistils. 



With thc same cxceiitiou — Surrey — it is au ascending order for variability of 

 petais. 



(c) The ascending order for means or variabilities of stamens or pistils is an 

 ascending order for the three correlations between stanii'os, pistils and ])elals. 



