ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 197 



Irritability. 



Influence of Electricity on Plant-development.* — F. Kovessi con- 

 tributes a note upon the effects produced on plants by currents of elec- 

 tricity. The experiments were made chiefly upon Triticiwi sativum, but 

 were afterwards extended to numerous other plants, including: herbaceous 

 and woody flowering plants, Mosses, Algse, and Fungi. The author is 

 convinced by his results that currents of electricity are detrimental to 

 the development of plants, but results are much modified, not only by 

 the nature of the electricity (potential, intensity, etc.) but also by 

 physical and biological factors, e.g. heat, humidity, light, nutrition. 

 The conductivity of the chemical components of the plant and its food 

 also play an important part. 



The author will publish shortly a full account of his experiments, 

 which deal with over 2,000,000 plants and were made under a variety 

 of conditions. 



General. 



Seeds as Microscopic Objects.! — ^- E. Brown describes a number 

 of seeds, probably unknown to the majority of microscopists, which 

 make beautiful or interesting microscopic objects. They belong to the 

 following species : — Eucharidiwn concinnum (Onagracese), a native of 

 California, known in cultivation ; Datisca cannabina (Datiscaceaj), a 

 native of Western Asia, sometimes cultivated ; Gephalipterum Drum- 

 mondii (Composit^e), Western Australia ; Pterospora andromedm (Mono- 

 tropeae), an extremely beautiful seed, a native of North America ; 

 Nemesia strumosa (Scrophulariacese), a well known garden plant, several 

 species of the genus have very pretty seeds ; Picrorhiza Kurrova 

 (Scrophulariacege) ; Pauloivnia imperialis and P. Fortunei (Scropha- 

 lariaceai), of Japan and China respectively ; Angelonia saUcariifolia 

 (Scrophulariaceae), and A. integerrima, natives of tropical America, 

 occasionally cultivated ; Orthocarpus sp. n. (Scrophulariaceae), natives of 

 Chile, California, etc. ; Sesamum capense (Pedalinete), from South 

 Africa ; j3^schy)imithus (jrandiflorus, and other species (Gesneraceae), 

 natives of tropical Asia, several in cultivation ; Philydrum lanugino- 

 sum (Philydrace^), China, Malaya, etc., sometimes cultivated. The 

 writer also refers to the Brazil Xut as of interest to microscopists, and 

 describes his method of mounting seeds to obtain the l)est results. 



CRYPTOGAMS. 



Pteridophyta. 



(By A. Ctepp, M.A., F.L.S.) 



Biology of Equisetum.l — Iv. Ludwig has studied the biology of 

 Equisetum. 1. The rhizome and aerial shoots of Equisetam differ in 

 form, especially at their apices. The leaves of the rhizome persist much 

 longer ; they bear hairs, which on the upper side protect the growing 

 point, and on the lower side they produce slime, which facilitates the 



* Comptes Rendus, civ. (1912) pp. 289-91. 



t Joiirn. Quekett Micr. Club, xi. (1911) pp. 307-12. 



+ Flora, n.f., iii. (1911) pp. 385-MO (figs.) 



April 17th, 1912 P 



