PEOFESROT^ K. PEARSON AXP* OTHERS ON 
280 
Page 
Section IV.—(16.) Ferns ..326 
(17.) A. (Scbloimidriuni vulrinre )—Somersetshire Series.327 
(18.) B. Ceterach {Ceteracli officinanm )—Somersetshire Series.331 
Section V.—Veins in Tnnics. 
(19.) The Onion {Allium cejXf)—Great Hampden Series.333 
Section VI.—Leguminous Plants. Seeds in Pod. 
(20.) The Broom {CiitiAus .scojMriiis )—Yorkshire Series.334 
V. Cross Homotyrjc axd Index Correlatioxs. 
(21.) The Mnahroom {ylf/ariciix camj)esfri!<) ..337 
(22.) The AVild Ivy {IMera heli.r) .346 
VI. SiAAr^rARY OF Results. 
(23.) Relation of Homotypic and Fraternal Mean Correlations.3i5.'5 
(24.) Relation of IndiA'idual and Racial Varialhlities.359 
(25.) Possibility of Relation l>etween Homotyposis or Heredity and Variabilittu No 
evidence of changing intensity of any of these with evolutionary Descent. . . . 360 
(26.) Brief rc.^irme of Conclusions reached.362 
Appexdtx.-— On the Homotyposis of the Seed-vessels of Leguminous Plants. ... 364 
I. Introdfctoeaa 
(I.) The present paper endeavours to deal tvith a problem upon tvhich I have long 
1)een occupied, adopting the widest basis compatible with the time and means at mj' 
dis 2 :»osal. In the first place, I have often been impressed with the small reduction in 
varialtility which cari he produced Ity selection. The offspring of a single j^arent 
while diverging in character, possildy very widely from the average character of the 
race, will still have a variability in that character only slightly reduced, say at most 
10 per cent, below the racial variability. Even if we select the ancestry for an 
indefinite number of generations, the offspring will have a variability ipjwards of 89 
per cent, of that of the original race."'" Now this capacity in the ])arent for pro¬ 
ducing variable offspring must be in some manner related to the degree of resemblance 
in those offspring. We have thus the two fundameiital divisions of our subject : 
(i.) What is the ratio of individual to racial variability ? 
(ii.) How is the variability in the individual related to inheritance Avithin the 
i-ace ? 
1 must endeavour to explain my meaning a little more fidly and clearly. The 
individual puts forth a number of like organs, corpuscles in the blood, petals of tlie 
flower, leaves of the trees, scales on tlie Aving. These may or may not he diAuded u]) 
into differentiated groups. Special forms of leaA’es occur in the neighbourhood of the 
fruit ; florets may l)e differentiated according to their position on the floAver, scales 
* “ On tlie Laiv of Ance.stral Heredity,” ‘ Roy. Soc. Proc.,’ vol, 62, p. 400, 
