14 



i:sTEODUCTOEY. 



fruit, while in tlie Strawberry, it is tlie large and pulpy receptacle 

 which is eaten. 



49. In the process of maturing, the walls of the ovary assume a va- 

 riety of texture. If they become soft and pulpy a Berry is formed, or 

 if the outer portion only becomes juicy and soft while the inner part be- 

 comes hard and bony, a stone-fruit or Drupe is produced (Fig. 81). 

 When the walls become thick or papery, we nave some form of a Pod, 

 or if bony, a Nu.t. The internal structure of the fruit is often different 

 from that of the ovary ; a several-celled ovary frequently producing a 

 one-celled fruit, the other cells, and often all the ovules but one, being 

 obliterated. It sometimes happens that more cells are present in the 

 fruit than were contained in the ovary ; this results from the formation 

 of false partitions. 



60. A pod formed of a single carpel, opening at maturity by its inner 

 or ventral suture, is a Follicle (Fig. 7) ; if it open at both sutures and 

 splits into two valves or pieces, it is called a Legume, of which the Pea 

 and Bean are familiar examples. A pod formed by a compound ovary 

 is termed a Capsule ; — if this opens by regular valves it is dehiscent, 

 otherwise indehiscent. Dehiscence may take place either by siolitting 

 through the partitions, when it is septicidal or through the back of each 

 carpel ; the latter m-ode is called loculicidal. That form of pod which is 

 peculiar to the Mustard Family is called a Silique (Fig. 23) ; this is 

 composed of two carpels, the two valves at maturity falling away from 

 the two parietal placentas which remain as a frame-work or Rcplum, — 

 in this the pod is two-celled by the stretching of a delicate false partition 

 between the two placentas, A short pod of this kind is called a Sdicle 

 or Pouch (Fig. 27). 



Some capsules open by a transverse line, the top coming off as a lid ; 

 such a pod is called a Pijxis and this kind of dehiscence, circumsissile. 

 (Fig. 42). 



51. A berry is a fruit, which like the grapC; is pulpy throughout ; if 

 the rind becomes hardened while the interior remaius soft, a Gourd-fruit 

 or Pepo is formed. A Pome, as the Apple and Pear, is composed of 

 the fleshy aud enlarged calyx-tube ; the carpels being the thin plates 

 which surround the'seeds in its centre (Fig. 90). Fleshy and pulpy 

 fruits are of course indehiscent. An Akene or Achenium is a small dry 

 one-seeded fruit, often popularly called seed, as in the Crowfoot (Fig. 

 6) and in the Composite Family (Fig. 126 & 140). A Grain or Caryopsis 

 is like an akene but with the pericarp closely adherent to the whole 

 surface of the seed. An Utricle is an akene with very thin walls. A 

 Key or Samara is a kind of akene with a wing, as in the Ash or Maple 

 (Fig. 68) ; in the latter case two are united. Multiple fruds result 

 from several flowers closely crowded together, as in the Mulberry. A 

 Cone or Strobile is a scaly-inbricated multiple fruit. 



52. The seed has already been described as containing an embryo 

 with or without albumen ; it has two coats, the inner of which is very 

 thin and delicate and not always to be made out, — the outer one, the 

 Testa, is much thicker and often even hard and bony, and is variously 



