ABSTRACTS. 



329 



from the incomplete material to hand he thinks the Togo plant is the 

 same. 



But the most interesting part of the paper is comprised in notes on 

 other kinds of Mahogany-yielding trees in Africa. 



The best-known African Mahogany is furnished by Khaya scnegalensis 

 (Juss.) of Senegambia and West Africa, and the author thinks the species 

 of Khaya yielding East African Mahogany may be different. 



But there are several other Swictenioidccc in Africa which furnish 

 Mahogany woods, of which Entandrophragma afigolense (Welw.), DC, 

 E. Candollei (Harms), and E. Casimirianum (Wild, et Dur.) of the 

 Cameroon and Congo regions are mentioned, as well as Wulfhorstia 

 spicata (DC.) in South-west Africa, and W. ckebcrgioidcs (Harms) from 

 the Zambesi. 



A still incompletely described form from Usamtara appears to be 

 .another Entandrophragma, and attention is drawn to the importance of 

 obtaining specimens. 



In conclusion the author describes a new species of Khaya, K. eury- 

 phylla (Harms) from the Cameroons, making a third Mahogany of this 

 genus, the other two being K. scnegalensis (Juss.) and K. anthotheca 

 (Welw.), the latter from Angola. 



In reading this paper one is struck with the importance of having 

 more complete information regarding these African Mahogany trees, as 

 al>o with the increasing tendency to widen the connotation of words like 

 " Mahogany," "Cedar," &c, in different countries; in Australia, for 

 instance, the word " Mahogany " is applied to timber of various species of 

 Eucalyptus, trees belonging to the Myrtacece, a natural order of quite 

 different affinities from Mcliacece, much as " Cedar " is applied to wood 

 from certain Conifers (Juniperus Ceclrus), as well as to that from Cedrela 

 (Meliacece).—H. M. W. 



Maize : A Study of the Fertile Hybrids produced by cross- 

 ing Teosinte and Maize. By John W. Harshberger, Ph.D. (Gontr. 

 Bot. Lab. Phil. vol. ii., No. 2, p. 231, pi. 22; 1901).— The Teosinte 

 is described to be known in Mexico under that name, and botanically as 

 Euchlana luxurians. It is grown as a fodder plant in most warm 

 countries, seldom flowering when planted in Europe. 



Professor Segura, director of the School of Agriculture, City of 

 Mexico, has carefully cultivated the plant, and obtained seeds, by hybrid- 

 ising with the common Maize, which correspond with those of Zea 

 canina, so called by Watson, which latter is therefore a hybrid between 

 Euchlana luxurians, otherwise Euchlama mcxicana, and the common 

 Maize. The question is raised, whether Zea Mays is a true species, or a 

 cultivated race or variety of Euchlcena mcxicana. Or, is Indian Corn a 

 species of Euchlcena closely related by consanguinity to Euchlama 

 mcxicana ? These questions can only be answered by the discovery of 

 the wild plants concerned in the problem of the origin of Maize. 



31. C. C. 



Manures, Chemical.— Do they exhaust the Humus of Soils? 



By K. de Vries, of Groningue, Holland {Ann. Agr. p. 113 ; September 



