LECTURE IX. 
CONCLUSION OF VEGETABLE TISSUES. 
Having in my last Lecture completed the description 
of all the important tissues entering into the formation 
of vegetables, I shall now pass on to consider those 
composing the animal body ; but before doing so, I pro- 
pose to take a rapid review of the subjects which have 
occupied our attention since the commencement of this 
course. 
I stated in my first Lecture, that all plants were made 
up of an elementary membrane existing in the form of 
cells, each of which in the young state is provided with 
a nucleus or cytoblast and nucleoli ; the membrane 
being generally of a greenish colour, but, in Ferns , 
occasionally brown. The membrane in process of growth 
becomes thickened by secondary deposit ; this may be 
either in a homogeneous form, and occupy the whole 
