Tl^e Sources of the Nitrogen of our Leguminous Crops. 683 
and less also of nodules, than in the pots with soil-ex- 
tract only. 
I Lastly, witlwnt soil-extrad seeding, and with no nodules, there 
was no gain of nitrogen; v:hiUt,v:ith soil-extract, and u-ith 
numerous nodules, there u-as considerable gain of nitrogen ; there 
being, loith much less nitrogen in the seed, and about the same 
j ammmt in the products, as in the crjrresponcling experiments ivith 
I peas, verg mang times as much nitrogen in the vegetable matter 
produced as in the seed sown. 
As already said, the experiments with blue lupins failed. 
Those with yellow lupins, however, gave very striking results. 
As in the case of the other plants grown in 1889, the yellow 
lupin seeds were sown on July 10, three being put into each 
pot. There were some re-sowings, some seeds taken out, and 
eventually two plants were left in each pot. By the end of 
July the plants in pots 2 and 3, with the lupin soil-extract 
seeding, already showed more growth than those in pot 1 with- 
out it. Photographs of the plants were taken on August 3, 
August 20, September 27, October 28. and November 29; and 
the plants were taken up on December 7. 
The plants in pot 1, without soil-extract seeding, scarcely 
appeared above the rim of the pot, one being only about 1|, and 
. the other only 2| inches high. In pot 2, with lupin soil- 
. extract seeding, one plant was about 24, and the other 18| 
inches high ; both spreading much beyond the width of the 
pot. In pot 3, also with lupin soil-extract seeding, one plant 
was more than 24, but the other little more than 8 inches high, 
lu fact, in both the pots, with quartz sand, ash, &c., and soil- 
I extract seeding only, the plants developed considerably more 
than those in pot 4, with the lupin-soil itself; one of these 
I being only about IG inches, and the other about inches 
high, and both less branching than those in pots 2 and 3. 
Unlike the peas and vetches, the yellow lupins, with soil- 
extract seeding only, flowered and podded freely. Thus, in pot 2, 
one plant flowered only, but the other had nine small pods ; 
and in pot 3, one had four large and three small pods, and the 
other a flower forming. There were also in pot 4, with lupin- 
soil, on one plant five pods, and on the other, six. The 
general result was that, iji the quartz sand with lupin soil- 
extract seeding, the plants not only produced a great deal more 
vegetable matter than those in the lupin sand itself, but they as 
freely flowered and seeded. 
In pot 1, without soil-extract, and very restricted above- 
ground growth, there was coincidently very little root develop- 
