188 ORGANOGRAPHY. BOOK I. 



magnitude of two feet in diameter ; and from the texture of a 

 delicate membrane to tlie coarse fabric of wood itself, through 

 various cartilaginous, coriaceous, bony, spongy, succulent, or 

 fibrous gradations. 



The base of the pericarp is the part where it unites with 

 the peduncle ; its apex is where the style was : hence tlie 

 organic and apparent apices of the fruit are often very dif- 

 ferent, especially in such as have the style growing from 

 their sides, as in Rosacea; and Chrysobalaneas, Labiatae and 

 BoraginesB. 



When a fruit has arrived at maturity its pericarp either con- 

 tinues perfectly closed, when it is indehiscent, as in the hazel- 

 nut, or separates regularly round its axis, either wholly or 

 partially, into several pieces : the separation is called dehis- 

 cence, and such pieces valves ; and the axis from which the 

 valves separate, in those cases where there is a distinct axis, is 

 called the columella. 



When the dehiscence takes place through the dissepiments 

 it is said to be septicidal ; when through the back of the cells 

 it is called loculicidal ; if along the inner edge of a simple 

 fruit it is called sutaral ; if the dissepiments are separated 

 from the valves the dehiscence is named septifragal. 



In septicidal dehiscence the dissepiments ^^8 



divide into two plates and form the sides of ^/\a /, 



•tL^- a 



of dehiscence the valves were alternate with / \ 



the dissepiments, or that the valves had <^ ^ 

 their margins turned inwards. This may v 



be understood from ^y. 168., which represents the relative 

 position of parts in a transverse section of a fruit with septi- 

 cidal dehiscence ; v being the valves, d the dissepiments, and 

 a the axis. 



In loculicidal dehiscence the dissepiments 

 form the middle of each valve, as in the lilac, 

 or in the diagram 169., where the letters 

 have the same value as above. In this it 

 was formerly said that the dissepiments were 

 opposite the valves. 



each valve, as in Rhododendron, Menziesia. / \ 

 &c. Formerly botanists said that in this sor 



