PHYSIOLOGICAL BOTANY. 269 



A. St. Hilaire also treats of this point in his ' Morpho- 

 logic Vegetale/ pp. 185-6, and says, in opposition to the 

 view that the tendril occurs on one side of the leaf, that 

 we find on one side of the leaf a developed stipule, and 

 on the other an abortive one (Ervum monanthos), and that 

 it is but a small step from this to its complete absence (?). 

 Moreover, in one of the Cucurbitacese in the garden at 

 Paris, he had noticed two tendrils. My ' El. Ph. Bot.' 

 were published as early as 1837, the 'Morphologic' in 

 1841. M. Tassi must extend his inquiries beyond what 

 is done in Italy. 



New Researches upon the Structure of Cistomes. By 

 GUGL. GASPARRINI. Naples, 1844, 4. The author has 

 previously described a pouch or sac, which is adherent to 

 the stomata internally. He calls these sacs cistomi, be- 

 cause they are attached to the stomata (stomi). In the 

 present short communication he now describes a canal 

 which arises from the sacs. His investigations were 

 principally made upon Cactus Peruvianus, then upon 

 Ornitliogatum nutans, and Arum Italicum. I have also 

 examined Cactus Peruvianus, and have seen the sacs but 

 not the canal, which the author himself has only figured 

 in some, not in all. But the epidermis must be strongly 

 boiled with hydrochloric acid to exhibit the sac ; hence it 

 appears to be nothing more than the internal membrane 

 of the aerial reservoir, which the thicker epidermis (cuticle) 

 has entered and lined, as has already been remarked by 

 Mohl. Mohl has also found that the epidermis sometimes 

 extends into the cellular tissue, and there forms, as it 

 were, canals. Too strong treatment with acids materially 

 destroys the connexion of the parts, so that the true 

 structure is no longer recognisable ; and this is the case 

 in the present instance. I have not been able to find the 

 canal which the author figures from Ornithogalum nutans. 



C. MULLER has communicated to the 'Bot. Zeit./ 

 1845, p. 793, Some observations on the Resinous Exudations 



