1V PREFACE. 
While the study of Morphology and Classification may 
he conducted in comparatively large classes with inexpen- 
sive apparatus, that of Histology and Physiology, and of 
the structure of cryptogamic plants, requires conditions 
which are difficult of attainment in schools—namely, small 
classes and somewhat expensive apparatus. I therefore 
here only give the first two years’ work of a school course 
which ought to cover a period of at least three years, the 
third year being devoted to an introduction to microscopic 
botany. 
If scientific work is to take the place in our schools 
which modern views seem to demand, then it must in the 
first place be thorough and practical, and a sufficiency of 
time must be devoted to it. ‘Two hours a week for a period 
of three or four years is not too much to demand for this 
branch of science; but no provision has hitherto been 
made in the way of providing text-books for such a 
thorough study of the subject. This must be my excuse 
for adding one more to the many works which profess to 
teach the science of Botany. 
G. M. T. 
