88 



FRUITS 



and woody. It encloses a single, oily seed so deeply hollowed out as 

 to be cup-shaped. This cup-shaped hollow is completely filled by 

 two parallel, lenticular ingrowths of the endocarp and mesocarp, 

 which can easily be seen by cutting a fruit longitudinally through the 

 median line of the carpel and removing the two halves of the seed, or 

 less clearly by cutting the fruit transversely. The seed exhibits a 

 crescent-shaped section when cut either longitudinally or transversely. 

 Cocculus indicus has no odour ; the pericarp is tasteless, but the seed 

 is very bitter. 



FIG. 49. Cocculus indicus. A, vertical ; B, transverse section ; 

 p, pericarp ; n, base of fruit ; E, seed ; /, fold of pericarp. 

 Magnified. (Moeller.) 



The student should observe 



(a) The sub-reniform shape of the fruit, 

 and should cut it longitudinally and transversely, noting 



(6) The shape of the seed, 



(c) The characteristic ingrowths from the pericarp. 



He should further notice that the seed is bitter, but the pericarp is 

 almost tasteless. 



Constituents. The seed contains from 1 to 1-5 per cent, of an 

 intensely bitter, crystalline principle, picrotoxin, accompanied by a 

 crystalline but tasteless body, cocculin, and a large proportion of fat. 

 Picrotoxin, 45 H 50 19 (m.p. 199), contains no nitrogen and is there- 

 fore not alkaloidal, nor does it possess glucosidal properties. It is 

 readily separable into toxic picrotoxinin, C ]5 H 16 O 6 , and non- toxic 

 picrotin, C 15 H 18 7 , but its further constitution is as yet unknown. 



From the pericarp, which is tasteless, two alkaloids, menispermine 

 and paramenispermine (Pelletier and Couerbe, 1833) have been isolated 

 but they require re-investigation. 



