134 Meyen's Report for 1839 on Physiological Botany. 



in unrollable spiral fibres. The fibres were extracted from the 

 flower-stalks of the above stems with all possible care ; and 

 this was best effected by breaking the stalk into short pieces, 

 drawing the ends about an inch or an inch and a half asunder, 

 and then taking away the extracted fibres with a pair of 

 wooden pincers, and throwing them directly into water, in 

 order to free them in the first place from the adhering mucus, 

 and secondly, from the tannic acid, from the presence of which 

 they acquire a brown tinge when exposed to the air. The 

 wool obtained in the above manner is equal to the finest 

 sheep's wool, and surpasses it in whiteness, as also in the finer 

 and more regular curling of the single filaments. The quan- 

 tity obtained from the two stems was so considerable, that an 

 artisan wished to make a glove out of it ; and therefore it could 

 not be difficult to obtain such large quantities of this material 

 in the tropics (where every year thousands of pisang stems 

 are cut down in some localities) as to be able to prepare va- 

 luable stuffs ; indeed, shawls made of the fibres of the pisang 

 could not be so expensive as the Persian ones. 



MM. P. Savi and G. B. Amici* have made some communi- 

 cations concerning the stomata of plants. The observations 

 of M. de Cesati on the stomata of Ambrosinia Bassii, which 

 have not been confirmed by MM. Savi and Amici, were the 

 cause of the research. M. tie Cesati thought that he had ob- 

 served a very peculiar structure in the cuticular glands and 

 stomata of Ambrosinia Bassii ; he speaks of a glandulous 

 matter of which the outer edge of the stoma consists, which 

 thereby presses apart the sides of the four inclosing cells. 

 The real cleft is destined for the evaporation alone, whilst one 

 of the two glandulous pads or circles is destined for the sepa- 

 ration of carbon, the other for that of oxygen, &c. M. Savi 

 examined Ambrosinia as far as regards its stomata, and found 

 them similar in structure to those of other plants, as is shown 

 by the figures ; the stomata are usually formed by two semi- 

 lunar cells, but they are covered by a second cuticula, which 

 also exhibits a longitudinal cleft ; even in the figure of a trans- 

 verse section through the middle of such a stoma, this cuticle 

 is represented with its slit. M. Amici also, in his answer to 

 M. Savi, has confirmed the above statement with respect to 

 the structure of the stomata of Ambrosinia. Finally, M. Amici 

 proves that the jjriority of the discovery of the stomata in the 

 bottom of the deep pits on the lower surface of the leaves of 

 Neriuni belongs to him, inasmuch as he communicated this 



* Osscrvazioiii siiUa slrultura ed csisttnza degli sloiiii in alcuiie plante, 

 &c. Mem. della R, Acad, dellc Sc. di Torino, Serie ii. torn. ii. p. 19. 



