95 



fed c 



[Fig. 1, Forms of tissue; a, cutting of elder pith, cellular; b, cells 

 from the gritty centre of the pear; c, from the stone of the plum both 

 strengthened by solid matter; d, woody fibre; e, spiral vessel with a 

 single fibre partly drawn out; f, vessel with a quadruple fibre. Wood.~\ 



The several elementary structures of which the various 

 parts of plants are made up, are called elementary tissues: 

 they are five in number, viz: the cellular, woody, vasiform, 

 vascular, and laticiferous. The chemical elements of which 

 these tissues are composed, are enumerated and described in 

 works on chemistry. 



Cellular tissue is composed of a series of minute cells 

 attached together, and having a more or less regular form. 

 Fig. 1, a. 



Woody tissue consists of minute tubes, tapering to a point 

 at both ends, and adhering by their sides, the end of one tube 

 overlapping that of another so as to" form continuous threads. 

 Fig. 1, d. 



The vasiform tissue consists of tubes, large enough to be 

 seen by the naked eye in some plants, as, for example, in a 

 transverse section of the oak. In some plants these tubes are 

 jointed, or divided by partitions, and in others they arc con- 

 tinuous. It is through these that the sap rises, and they are 

 the largest vessels in the vegetable organization. Fig. 2, a. 

 Vascular tissue consists of spiral vessels, resembling some- 



