[Vor. 7 
204 ANNALS OF THE MISSOURI BOTANICAL GARDEN 
Green 7ft.in Grams 
E 
24 
EY! 
20 
Cotyledons excised 
6 
Immediately 2 das. 7 das. Control 
Fig. 1. Green weight quantities of Canada field peas 
in various solutions as affected by cotyledon excision. 
of peas, at a mean temperature of about 15.6°C. The technique 
was the same as above described, but the use of organic sub- 
stances in the solutions made it desirable to renew the solutions 
every 3 or 4 days in order to reduce or control bacterial action. 
The complete results are shown in table 11, and in fig. 1. It 
will ultimately be necessary to extend the use of organic sub- 
stances and to repeat this work under pure culture conditions. 
In fact, a small series of experiments in this direction has already 
been performed, but inasmuch as these are to constitute a part 
of a more extended study I will confine myself here to a brief 
discussion of the data presented below. 
In general it will be seen that whatever the medium employed 
as a nutrient solution the removal of the cotyledons is shown 
by marked depression in the growth rate. The mineral nutrient 
solution employed in this case is that which I have in a previous 
