404 
LOCK : STUDIES IN PLANT BREEDING 
smooth, and nearly spherical, but being closely packed in the pod 
they exhibit a certain squareness of outline. Cotyledons yellow ; 
starch grains of the round type. The testa shows fine dots of a deep 
purplish colour and, in addition, a marbling of brown on a pale 
greenish-yellow ground. The purple colouration is produced by a 
pigment dissolved in the sap of certain cells immediately underlying 
the outermost layer of the testa. The brown colour is almost or 
quite confined to the walls of the I-shaped cells of the outermost 
layer. The greenish colour seems to be a solid pigment deposited in 
all or nearly all the cells of the testa. 
I have received a closely similar pea from the Superintendent of 
the Calcutta Botanic Gardens under the name of Pisum quadratum. 
The habit of the plants is slightly different, but in other respects they 
closely resemble one another. Certainly no one would at first sight 
place these plants in the same species as the ordinary forms of Pisum 
sativum grown in Europe. The former have in comparison a primi¬ 
tive and wild appearance, and the suggestion that they may lie 
somewhere near the original ancestor of European cultivated peas 
is supported by the fact presently to be described in greater detail, 
that on crossing with the white-coated form Satisfaction there were 
obtained in F 2 all the best known types of testas to be found in 
.cultivated peas. 
B .—The Cross-bred Forms. 
1. Native pea No. 2 x Satisfaction .—Only one cross (No. 440, made 
in January, 1903) was successful ; and various accidents prevented 
me from obtaining further crosses. Three seeds were produced, quite 
indistinguishable from the other seeds of the same plant so far as 
appearance was concerned. The seeds were sown on May 2, but 
only one plant produced seed. This plant was 70 inches in height 
and had 31 nodes. The average width of its 4 pods was 14 mm., and 
these contained altogether 8 seeds. The plant and its seeds resem¬ 
bled those produced upon the plants of the reciprocal cross, and they 
may be described together. 
2. Satisfaction x Native pea No. 2.—Two successful crosses gave 
rise to 6 seeds which were gathered on February 17, 1903. These 
seeds closely resembled those of Satisfaction except in being filled 
