H. EPPS ON THE KOLA BEAN. . 6 



lants for some days without feeling nausea. There seems here an 

 ample field for the physiological investigator, and if only a few 

 intelligent (!) inebriates could be provided, for sobering experiments 

 to be made upon them, the startling claim (among others) made for 

 the Kola bean, of being a remedy for dipsomania, might be verified. 

 This, however, is not the function of a microscopical society such 

 as ours. 



The microscopic examination of the Kola bean has not yet pro- 

 ceeded very far, and there must still be much to illustrate. I have 

 on view to-night several sections of the dry bean, which show very 

 clearly the brownish-yellow cell-walls of the tissue, packed closely 

 with granules of starch. The Kola bean of commerce, dry, brown, 

 roundish, about 1-^ inches in size, is of a hard, tough, almost 

 flinty character, but in its fresh state, in which state I have obtained 

 samples, it is soft and succulent, lending itself readily to the pro- 

 cess of cutting up into sections. 



I will .now proceed to mention the various points of micro- 

 scopical interest that I have as yet met with, in both the fresh and 

 dry bean. 



The mass of the cotyledonary tissue is composed regularly of 

 cells, generally sexagonal, packed full of starch granules, these 

 becoming more and more numerous with increased distance from 

 the surface. The cellular tissue presents no particular feature of 

 interest. The cells themselves vary in diameter from '0012 to 

 •0020 of an inch, and each cell contains (when observed in 

 section) from 8 to 15 starch granules. The latter vary in size 

 from "00025 to *0005 of an inch ; are oval but rather irregular in 

 shape, somewhat like Natal arrowroot, but smaller. There is 

 generally a deeply marked hilum visible in the centre of each 

 granule, which under the polariscope appears traversed by a very 

 regular cross, and with the addition of a plate of selenite the 

 granule is very clearly divided into pure red and green sections. It is 

 in the tissue walls that the alkaloids caffeine and theobromine are 

 to be found in an uncombined form, and remembering the large per- 

 centage (2*8) present, it should be comparatively easy to obtain 

 them for microscopical examination. 



The epidermis, which in the fresh bean is the principal seat of 

 the colouring matter, is composed of a layer of oblong-shaped 

 cells measuring about -001 of an inch, and there are other layers of 

 cells lying beneath, varying in size from '001 to '0003 of an inch. 



