94 LETTER VI. 



essential character of the Orange tribe ; on the con- 

 trary, it is peculiar to the Orange genus (Citrus) 

 only. In all the other genera the fruit is fleshy and 

 fragrant, but not pulpy in the inside. 



So few plants related to the Orange are ever likely 

 to be met with by you, that I should only fatigue you 

 unprofitably in repeating their names. Let us con- 

 clude, then, for this time with the essential character 

 of the Orange tribe, which, if reduced to its simplest 

 form, may be expressed thus : — 



Leaves, flowers, and fruit, filled with transparent 

 receptacles of fragrant volatile oil. Leaves jointed, 

 once at least, above the footstalk. Stamens few and 

 hypogynous. Fruit fleshy. 



To compensate for the length of some of my former 

 letters this is unusually short ; for which I suspect 

 you will be inclined to thank rather than to blame 

 me. 



EXPLANATION OF PLATE VL 



1. The Mallow Tribe. — A sprig of the larger Mallow (Malva 

 sylvestris). — 1. An anther witli the upper part of the filament. — 2. A 

 pistil, shewing the ovary, column-like base of the styles, and the 

 styles themselves — 3. A calyx closed over the growing fruit, with 

 leaves of the involucre at a. — 4. A ripe fruit ready to separate into 

 distinct carpels, — 5. One of the carpels separated from the rest, and 

 seen from its side. — 6. The same, split in halves, to shew the em- 

 bryo; from the position in which the embryo Ues, only one of the 

 cotyledons can be seen at a; b is the radicle. 



IL The Orange Tribe. — A twig of the common sweet Orange. 

 — 1 . A flower shewing the calyx, the petals spotted with oil, and the 



