HOMOTYPOSIS IN THE VEGETABLE KINGDOM. 
3:3!) 
by individuality. Thus we shoiddfind the degree of resemblance between two gills of 
the same mushroom, when measured by length or breadth, to he influenced not only 
by the individuality of the mushroom, ljut by the stage of its growth, and 
accordingly likely to exceed, and 230ssihly considerably exceed, the value about ‘5, 
which we have determined in several other cases. 
In order to make a more complete study of the influence of stages of growth on 
the degree of resemblance of undifferentiated like organs. Dr. Lee with her 
characteristic energy undertook the five needful tables. 
They are the following - 
(i.) Organic correlation of the length and breadth of the same gill. 
(ii.) Homotypic correlation of the lengths of two gills of the same mushroom. 
(hi.) Homotypic correlation of the breadths of two gills of the same mushroom. 
(iv.) Cross homotypic correlation of the length of one, and the breadth of a second 
gill of the same mushroom. 
(v.) Homotypic correlation of the indices of two gills of tlie same mushroom. 
Of these tables the cross homotypic correlation between length and breadth is a 
very laborious business, offering no means of readily testing the accuracy of the 
entries until the whole table is completed and its columns and rows added up. 
Ultimately the frequency distributions (as given by row or column marked totals) 
for the lengths and breadths in tables (ii.), (iii.), and (iv.), ought to be n — 1 times the 
frequency distributions of lengths and breadths as given by the like row and column 
in the organic correlation table (i.), n being the number of organs measured in each 
individual; in our case this is ten. 
I begin by C(3nsidering the results obtained for the degree of resemblance of gill- 
indices, he.. Table (v.) referred to above. The following were the results obtained : — 
Mushroom. Gill Indices. 
Number of 
Mean index. 
S. D. 
Coefficient 
of 
variation. 
S. D. of 
array. 
Percentage 
variation. 
Correlation. 
Mushrooms. 
Gills. 
I’airs. 
107 
1070 
96.30 
2-8695 
± -0108 
•5246 
± -0076 
18-2819 
•4385 
83-58 
•5490 
[± -0144] 
The frequency distribution of the gills was the following : — 
* The absurdity of disregarding tlie growth-factor may I»e realised if we consider how' much the degree 
of resemblance in brethren would l)e increased if we took pairs of brothers, differing, say, by less than two 
years, and these pairs were scattered at all ages from four to twentj'! 
■> Y 
^ .A. i.’ 
