138 



ACADEMIC JBOTAJVr. 



the Castor-Oil it is a thick, fleshy disk (Pig. 195, C) ; in the Polygala 

 it is three-lobed and fleshy. In the Spindle-tree it becomes a free, 

 succulent bag around the s"eed ; in the Nutmeg (Fig. 196) it becomes 

 the free, fleshy, honeycombed, and laciniate envelope known as mace. 



These forms are called 

 Arillodes, or false arils. 



319. The Chalaza is 

 often appendaged. In the 

 Willow-herb (Fig. 75, 3) 

 it is comose (like the mi- 

 cropyle of the Milkweed), 

 and is called a Strophiole 

 (L. strophiolum, garland). 

 in the Aristoloehia it is 

 fleshy, and called a Car- 

 uncle (L. ciirunculus, small 

 bit of flesh). 



320. The Raphe is often 

 invisible externally ; but 

 in the "Wild Ginger (Fig. 

 195, B) it is prominent, 

 and also in the Heart's- 

 ease and Celandine, form- 

 ing a crest on the side of 

 the seed. These enlarge- 

 ments are called Strophi- 

 oles, or Caruncles. 



821. The Funiculus is usually short exteriorly, or wanting. In 

 the Plumbago Order it is finely developed. Here (Pig. 195, D) the 

 ovary is one-celled ; its single ovule is anatropous and suspended from 

 a long funiculus fixed at the base of the cell. The funiculus is often 

 appendaged with accessory (helping) organs called Arils. In the 

 Yew the aril is the red succulent cup which envelops the naked seed. 

 In the Willow it is comose, completely hiding the seed. In the 

 Prickly Pear it at first consists of two boat-shaped expansions spring- 

 ing laterally from the funiculus ; the ovule is developed within 

 these ; they afterwards harden into an accessory envelope, which be- 

 comes a sort of stone covered with pulp. In the White Water-lily 

 (Nympheea) it is a free, transparent hag, nearly closed, prolonged 

 beyond the enveloped seed; in the Passion-flower it is similar, but 

 fleshy and with a large opening. 



322. The Hilum, or Eye, is sometimes hardly discernible, as in 

 the Canna ; but frequently it is conspicuous, as in the Pea Family. 



323. Seeds are easily dissected, as a rule ; no implements 

 are needed for this purpose except a careful eye, patient 

 fingers, and a needle, pin, or pocket-knife. The study 

 of their parts is the most important as well as the most 

 interesting branch of botanical science. 



Fia. 196. — Nutmeg {Myristica moecluLta). 



