THE JOURNAL OF PHARMACOLOGY. 35 



to be poisonous"to about 2-3 of those who handle them, the effects extending 

 only to those parts of the body which are exposed to contact with the 

 fruit. Much discussion has taken place in relation to the nature and origin 

 of this poisoning, which takes the form of a fine rash, something like that 

 produced by our poison ivy. It is impossible to discuss this question here, 

 but I may say that it has seemed to me, after all that I have read in re- 

 lation to it. that this is most likely di\c to the numerous needle-like crystals 

 of calcium oxalate which exist in the bean, than to anv other cause. 



THE MICROSCOPICAL CHARACTERS OF VANILLA. 



By Smith Ely Jelliffe, M.D. 



STRUCTURE OP THE ERUIT. 



In general it may be said that the different varieties of the vanilla fruit 

 have an analogous structure. The form we have here is about 25 cm. long, 

 about 10 mm. wide and (i mm. thick. The color is a rich dark brown, and 

 it has an oily to resinous feel. It is longitudinally wrinkled and covered 

 with a whitish crystalline deposit of vanillin. 



A transverse section shows that the fruit is elliptical, and the moderately 

 thick walls enclose an irregular triangular- cavity, into which several rib-like 

 processes extend. These are the placentae, and support the fine black seeds, 

 which are very numerous. Each placenta is two-ranked. The interior of 

 the cavity of the ovary is filled with minute papillae, to be mentioned later 

 under microscopical considerations. 



The external surface of the fruit is the epicarp, which is composed of 

 thick-walled regular cells, disposed in a single row. Beneath this the 

 tissues are very thin- walled and lax, containing considerable amounts of an 

 oily substance with the characteristic odor of vanillin, and also containing 

 a, large number of fine acicular crystals of calcium oxalate. These axe in 

 general larger than the crystals found on the exterior of the fruit. The 

 polygonal cells of the mesocarp are finely pitted in the main, but a number 

 of them, (specially near the periphery, are irregularly marked. 



In the mesophyll are the fibro-vascular bundles. These are irregularly 

 scattered, the external ones being somewhat radially disposed, while those 

 further in are not infrequently tangentially arranged. The bundles are 

 loose and lax, and are built on the concentric type. In the centre of the 

 bundle the fibres and sieve-tubes are found. These are surrounded by a 

 number of ducts, which are usually spiral in type, and sometimes inter- 

 spersed with annular ducts. Irregular resinous masses and prisms of va- 

 nillin may be found in the tissues of the mesophyll. 



The innermost layer of the mesocarp is made of smooth, slightly flat- 



