338 
The Ohio Naturalist 
[Vol. V, No. 7, 
crossed it frequently occurs that the resulting hybrids exhibit 
the character from one parent only. The character which 
appears is said to be dominant while the corresponding character 
from the other parent not in evidence is called recessive. But if 
these hybrids are bred among themselves they give rise to 
offspring of two types, some showing the dominant character and 
some the recessive, and these usually appear in the proportion of 
3:1. By further trial it is found that about one-third of the 
dominant individuals are pure and two-thirds of mixed nature. 
(ji.re.ri ^e. 3-5 • | ^ener: | I 
r 
r 
Sri-i. n. 
■yc / 1 our 
(fiure) 
an 
ye.lh^ "S 
S^r£e n - 
( Pure) 
- e. ,v ^re. e n t 
2 . 
(lUi>e4) 
yi { 3 >r^e.n — - 3 re.^ n e en 
i[3reen 5'rcen 
-/I Jree 
I I fur 
5Lyel)oii''< 
7?ni;c«S) 
3< 
3{ 
2 l/c||o ur . 
3< 
e) 
/ l/el)our 
•'((Pure) 
.iye\\cuf± \ 
^ ^((Pure) 
-/ ^e\\o o’" Vc 1 1 Ug II oar 
. ((Pure) 
^ ^ellour- 
^ ( furt) '' 
\ V (furt) ^ -yell.v^ 3/eilour 
Fig. 4. Diagram showing the operation of Mendel’s law with peas having 
yellow and green cotyledons. 
These latter will again produce offspring of both types the same 
as the original hybrids, and so on for many generations. The 
first instance discovered by Mendel related to the color of the 
cotyledons in peas. The yellow color of cotyledons was found to 
be dominant over green. The operation of Mendel’s law as 
regards the yellow and green colors of cotyledons is shown in 
Fig. 4. Albinism among animals also furnishes a familiar exam- 
ple of the operation of Mendel’s law. If albino mice are mated 
wdth gray mice the offspring are gray, but in the following gen- 
eration one-fourth will again be albinoes. The gray is the dom- 
inant and the albino the recessive character. 
