364 Mr. T. A. Knicur on esculent Strawberries. 
posed species of each of the preceding genera would, I am very 
confident, be found. capable of breeding with, and being trans- 
muted into, each other, as to their external characters; and if 
botanical writers still choose to call such species, they ought cer- 
tainly to distinguish them from others, as secondary or trans- 
mutable species. The external form and character of each plant, 
as it came from the hand of nature, was probably sufficiently 
peculiar to render it readily distinguishable from those of every 
other species: but varieties of soil, of climate, and of culture ap- 
plied for other purposes, have so far mixed and confounded the 
primary characteristics of many species, that experiments, such 
as those above described, now afford probably the only source of 
decisive evidence. | 
XXIV. On 
