228 
Canadian Af/riculturc. 
It is worthy of note that the earthworm, the most useful of all 
animals in the soil, appears to be absent from the prairie, or is 
at least very uncommon. Professor Macoun informs me that 
he has never seen one on the prairie, nor has he ever heard of 
one being seen by the Dominion land surveyors. Of course, 
this is only negative evidence, but if the lowly annelid be not 
already a dweller in the prairie soil, it is difficult to imagine 
why it should not become so, save perhaps in the alkali lands 
and " bad lands." This absence is, however, probably apparent 
rather than real, for Darwin states * that " earthworms are 
found in all parts of the world," although he does not refer 
specifically to the American prairies. 
Soils. — The remarkable richness of much of the prairie soil 
of Manitoba arises from the accumulation for ages past of the 
excreta of animals, the ashes of prairie fires, and the decaying 
remains of plants and animals, in a loamy matrix resting upon 
a retentive clay subsoil. In 1882, between forty and fifty 
samples of soil, taken at intervals between Winnipeg and the 
Rocky Mountains, Avere exhibited at the Royal Agricultural 
Society's Show at Reading ; they were shown in glass tubes, 
four feet in length, each tube containing a core of the soil and 
subsoil from the surface downward. Three samples of the 
surface soils were submitted to Sir J. B. Lawes, F.R.S., and 
Dr. J. H. Gilbert, F.R.S., for the determination of the nitrogen. 
No. 1 was from Portage la Prairie, 5(5 miles west of Win- 
nipeg, and had probably been under cultivation for several 
years ; the dry mould contained 0"2471 per cent, of nitrogen. 
No. 2, from the Saskatchewan District, about 140 miles from 
Winnipeg, had probably been under cultivation a shorter time 
than No. 1 ; its dry mould contained () o027 per cent, of ni- 
trogen. No. 3, from a spot about 40 miles from Fort Ellice, 
might be considered a virgin soil ; the dry mould contained 
0'2500 per cent, of nitrogen. In general terms, these soils are 
about twice as rich in nitrogen as the average of the Rothamsted 
arable surface soils ; and, so far as can be judged, are probably 
about twice as rich as the average of arable soils in Great 
Britain. They correspond in their amount of nitrogen very 
closely with the surface soils of our permanent pasture land. 
At the recent meeting of the British Association at Montreal, 
Sir J. B. Lawes and Dr. Gilbert presented to the Chemical 
Section a paper " On some points in the composition of soils, 
with results illustrating the sources of the fertility of Manitoba 
prairie soils," and I am indebted to Dr. Gilbert for his kindness 
in revising a Canadian newspaper report, from which 1 proceed 
♦ ' The Formation of Vegetable Mould throncrh the Action of Worms," p. 120. 
