26 
fact radium has the power to induce new factor mutations and to 
break up chromosomes into parts which may be rearranged to 
form such compound types as Nubbin. It is planned to con- 
tinue the radium experiments in the near future. 
For the radium preparations used in these experiments, the 
authors are indebted to the Memorial Hospital, New York City, 
and the personal cooperation of Dr. Halsey J. Bagg, of the Hos- 
pital Staff. 
The Genetic Analysis of Garden and Field Peas (Pisum) 
By Orranp E. Wuire, Dorotuy I. NErr, 
and Mary ELLEN PECK 
Investigations on inheritance and variation in field and garden 
peas have been continued in 1926, along the lines mentioned in 
previous reports. Our original experimental stocks consisted of 
several hundred varieties and wild species collected through the 
assistance of many institutions and people from all over the pea- 
growing world. In addition to the importance of such a collec- 
tion for our own experimental work, we have been enabled to 
help others interested along similar lines by sending them seed 
of or information concerning the various types. Thus this col- 
lection has served to bring about interchange of ideas, and un- 
official cooperation between workers along this line in Sweden, 
Holland, England, Germany, Austria, Finland, Japan, Egypt, and 
various institutions in the United States. And this in turn has 
helped to prevent unnecessary duplication. 
Many of these varieties and species have peculiar and little 
known characters. Through crossing these different types, and 
studying the inheritance of the characters by which they differ 
and the relations of these characters to each other and to various 
environments, a better understanding of the laws underlying in- 
heritance and variation and of the importance of inheritance and 
environment in the organism’s make-up is obtained. Year by 
year new facts concerning the inheritance relations of pea char- 
acters are discovered, and these, when incorporated with those 
already known, serve not only to increase our understanding of 
how to make more desirable pea plants, but also more desirable 
plants and animals in general. 
