THE PISTIL. 



129 



inner one secundim (Fig. 250 c*). The secundine is very delicate, and is larger than 

 the primine, and usually protrudes through the opening, or foramen (Fig 250 0J, and 

 can be examined only at the earliest period. 



It has already been stated that the ovule is connected with the ovary by means of 

 a placenta, and a delicate cord, termed the umbilical 

 cord (Fig, 250 a) ; and this is universal, except in such 

 plants as have naked seeds, or seeds and ovules deve- 

 loped without ovaries (Fig. 249). Such are the Coniferoe 

 and Cycads, whilst the Mignionette has the seeds par- 

 tially naked. When it grows from the base, or near 

 to the base, of the ovary, it is called erect and ascending, 

 respectively ; and when suspended from the top, or near 

 to the top, is termed pendulous and suspended, respectively. 

 The relative position of the nucleus, coverings, foramen, 



and funis, is variable, and 



is important, since it enters 



into the classification of 



plants. In the normal 



position the base of the 



nucleus is next to the pla- 

 centa, and is marked by a 



hilum on the coverings at 



which the vessels enter, 



whilst its apex is directed 



to the foramen. Such an 



ovule is termed orthotropal 



(Fig. 248 a). When this arrangement is changed only 

 so far that the foramen is curved down so as to approach 

 the hilum, the expression campylotropal is employed 

 (Fig. 248 b]. In other cases the nucleus changes its 

 position : so that its poles are reversed, and its base is 

 removed from the hilum to the point most distant from 



it, whilst the foramen with the apex of the nucleus is brought near to the hilum. 

 This change is called anatropal (Fig. 248 c), as in the Apple, Almond, and Cucumber. 

 The terms amp hi tr opal and semi anatropal (Fig. 248 d and t), indicate that the two ends 

 of the nucleus are transverse with respect to the hilum. 



Whenever the nucleus has its base removed from its normal position at the hilum, 

 it is in danger of dying from want of nourishment, since thus it is separated from the 

 placenta and umbilical cord (Fig. 248 c), the source of its nutriment ; but this is 

 averted by the formation of a bundle of vessels called a rap he (Fig. 248 e), occupying 

 the ventral suture of the ovary, and passing from the hilum to the base of the nucleus, 

 where it distributes itself in a star-like form, termed chalaza. The chalaza, therefore, 

 cannot exist apart from the hilum without a raphe", and both are absent so long as 

 the base of the nucleus is in apposition to the hilum in the membranes. 



FRUIT. 



When the ovary and its contents, of which we have now treated, have arrived at 

 maturity, they are named fruit, and that quite independent of any edible qualify wLicli 



\OL. II. K 



Fig. 249. Representing a cone, 

 between the scales of which 

 the seeds lie naked. 



Fig. 250. Exhibiting the va. 

 rious parts of an ovule. 



a, the placenta, with its vas- 

 cular cord leading into 



e, the raph, which expands 

 at/, at the base of the nucleus, 

 and forms the chalaza. 



c, the priniine, with its fo- 

 ramen or exostouie, b. 



c*, the secundine, with its 

 foramen or endostome, bx. 



d, the nucleus, with its apex 

 g, and amniotic sac, h. 



