GLOSSOLOGY OF ANGIOSPERMS. 435 



differing as to the relative lengths of the stamens and styles ; these are 

 called heterogonous* or heteroatyled. When there are two forms, viz., 

 one in which the stamens are long and the styles short, and the other 

 with short stamens and long styles, the flowers are said to be dimorph- 

 ous, or more accurately htterogonoua dimorphous, and the forms are 

 distinguished as short-styled and lung-styled When, as in some spe- 

 cies of Oxalis, there are three forms, viz., long-, mid-, and short-styled, 

 the term trimorphous (or better heterogoiMis tiimorphoun) is used. 



The Fruit. The fruit may include (1) only the ripened ovary with its 

 contained seeds eg., the bean ; or (2) these with an adiiate calyx or re- 

 ceptacle e.g. , the apple. Many changes frequently take place in ripen- 

 ing, such as (1) an increase in the number of cells by the formation of 

 false partitions, or (2) a decrease in their number by the obliteration of 

 some ; (3) the growth of wings or prickles upon the exterior of the ovary ; 

 (4) the thickening and formation of a soft and juicy pulp; (5) the 

 hardening of some portions of the ovary wall by the development of 

 sclerenchyma ; (6) the thickening and growth of the calyx or recep- 

 tacle. 



In cases where in the ripening the ovary walls remain thin, and 

 eventually become dry, the fruits are said to be dry e.g., in the bean ; 

 where the walls become thickened and more or less pulpy, they are 

 fleshy e.g., the peach. These terms are also used in reference to the 

 fruit when it includes an adnate calyx or receptacle. In many fleshy 

 fruits (developed from carpels) the inner part of the pericarp wall is 

 hardened; the two layers are then distinguished as <x<>cnrp and endo- 

 carp ; when there are three layers the middle one is the me* arp. 



The opening of the fruit in order to permit the escape of the seeds is 

 called its dehis-ence, and sucli fruits are said to be dehiscent; those 

 which do not open are indehinr.ent. In fruits developed from single 

 carpels dehiscence is generally through the ventral or dorsal suture, or 

 both ; in those developed from compound pistils the partitions may 

 split, and thus resolve each fruit into its original carpels (septitidal 

 dehiscence) : or the dorsal sutures may become vertically ruptured, 

 thus opening every cell (loculus) by a vertical slit (loculicidal dthin- 

 cence). Among the other forms of dehiscence only that called circum- 

 cissile and the t/ regular need be mentioned ; in the former a transverse 

 slit separates a lid or cap, exposing the seeds ; in the latter an irregu- 

 lar slit forms at a certain place, and through this the seeds escape. 



The principal fruits may be distinguished by the brief characters 

 given in the following table :f 



* Proposed by Dr. Gray, Am. Naturalist, Jan., 1877. 



f This is based upon Dr. Dickson's classification as modified by 

 Professor Balfour in the article "Botany " in the ninth edition of the 

 " Encyclopedia Britannica," Vol. IV., p. 153. 



