Generate text from the speech, if possible.
IN DETERMINING WHETHER TWO OR MORE ALLIED FORMS OUGHT TO BE RANKED AS SPECIES OR VARIETIES NATURALISTS ARE PRACTICALLY GUIDED BY THE FOLLOWING CONSIDERATIONS NAMELY THE AMOUNT OF DIFFERENCE BETWEEN THEM AND WHETHER SUCH DIFFERENCES RELATE TO FEW OR MANY POINTS OF STRUCTURE AND WHETHER THEY ARE OF PHYSIOLOGICAL IMPORTANCE BUT MORE ESPECIALLY WHETHER THEY ARE CONSTANT